Apparently, some time back in 2002 someone opted in an address that didn’t belong to them to a marketing database. It may have been a hard to read scribble that was misread when the data was scanned (or typed) into the database. It could be that the person didn’t actually know their email address. There are a lot of ways spamtraps can end up on lists that don’t involve malice on the part of the sender.

But I can’t help thinking that mailing an address for 10 years, where the person has never ever responded might be a sign that the address isn’t valid. Or that the recipient might not want what you’re selling or, is not actually a potential customer.

I wrote a few weeks back about the difference between delivery and marketing. That has sparked conversations, including one where I discovered there are a lot of marketers out there that loathe and despise delivery people. But it’s delivery people who understand that not every email address is a potential purchaser. Our job is to make sure that mail to non-existent “customers” doesn’t stop mail from actually getting to actual potential customers.

Email doesn’t have an equivalent of “occupant” or “resident.” Email marketers need to pay attention to their data quality and hygiene. In the snail mail world, that isn’t true. My parents still get marketing mail addressed to me, and I’ve not lived in that house for 20+ years. Sure, it’s possible an 18 year old interested in virginia slims might move into that house at some point, and maybe that 20 years of marketing will pay off. It only costs a few cents to keep that address on their list and the potential return is there.

In email, though, sending mail to addresses that don’t have a real recipient there has the potential to hurt delivery to all other recipients on your list. Is one or two bad addresses going to be the difference between blocked and inbox? No, but the more abandoned addresses and non-existent recipients on a list there are on a list, the more likely filters will decide the mail isn’t really important or wanted.

The cost of keeping that address, one that will never, ever convert on a list may mean losing access to the inbox of actual, real, converting customers.

At the same time, I was internet friends with an employee of JPL. I’d met him, like I met many of my online acquaintances, through a pet related mailing list.

One Wednesday, The Onion published an article Mir Scientists Study Effects of Weightlessness on Mortal Terror. As this was the time when the Internet consisted of people banging rocks together, there was not an online link to Onion articles. But I was sure my friend at JPL, and all his friends, would appreciate the joke. That night I stayed late at the lab and typed the article into an email (with full credit to the Onion) and mailed it off to him.

As expected, the article garnered quite a few chuckles and was passed around to various folks inside JPL. What wasn’t expected was another friend, from totally different circles, sending me a copy of that same article 3 days later. Yes, in 1997 it took three days for information to be shared full circle on the Internet.

Information sharing is a whole lot quicker now, with things coming full circle in mere seconds. But that doesn’t make the information any more reliable and true. Take a recent article in ZDNet Research: Spammers actively harvesting emails from Twitter in real-time.

ZDNet links to a study published by Websense, claiming that email addresses on Twitter were available for harvesting.

That’s all well and good, but all ZDNet and Websense are saying is that email addresses are available for harvesting. I’ve not seen any evidence, yet, that spammers are harvesting and sending to them. This doesn’t, of course, mean they’re not, but it would be nice to see the spam email received at an address only shared on twitter.

Well, I have unique addresses and an un-spamfiltered domain. I went ahead and seeded a tagged address onto twitter. We’ll see if it gets harvested and spammers start sending to it. I’ll be sure to keep you updated.

If people are using legitimate email addresses that legitimately opted in and verified details, they should be required to have a log of which lists they opted in to. You are just asking to hurt legit mailers.

The underlying reasoning appears to be that no sender ever spams, and every recipient or spamtrap owner is just too dumb to remember what they signed up for. If the recipient maintains a list of where they sign up, then spam will be a solved problem.

This is not only an unpersuasive line of argument, it’s also pretending that mailboxes are full of opt-in mail that the recipient just forgot about signing up for.

I do keep track of where I sign up for things. This doesn’t actually help when I get spam. For instance, I know that the address ticketmaster keeps spamming for raves in London was never used to sigh up for anything. Yet ticketmaster keeps telling me it was. They, of course, can’t tell me when or from where, so I treat the mail as spam.

I know that another address did sign up at a client’s site in 2007 as part of an audit I was doing for them. In 2010 that address was leaked to (or stolen by) a bunch of affiliate spammers. In the last 18 months I’ve gotten over 19,000 offers to the address, none of which are related to the original signup. Many of those offers are from real brands, including some that have hired me to investigate their affiliate programs and larger delivery problems.

I know another address was used during correspondence with a vendor discussing payment terms. That address was never given to them to add to a newsletter. They mailed me anyway. I knew that the mail was spam.

Knowing what you signed up for and having a log of what you opted in to doesn’t do anything to stop a sender from sending spam. It also doesn’t help legitimate mailers who may end up with spamtraps on their list. In all of the above situations my knowing where the address was given doesn’t help me or the sender identify what part of their signup process is broken.

If, however, senders had a real audit trail for addresses, they could identify what import brought my address into their list. They could track the dodgy vendor that is selling them bad lists. They can identify the problematic import that brought employee address books into the newsletter database. They could identify what idiot used my email address to buy tickets in London.

If the senders knew what was broken, they could fix the problem and have more deliverable and more responsive mailing lists. Without an audit trail, however, they’re stuck with a bunch of addresses of unknown provenance.

I believe that spamtraps – for the professional marketer – are scare tactics that are no longer relevant. a professional marketer

I’ve talked about spamtraps in the past. I’ve described a number of different types of spamtraps and what they tell the trap maintainer about a sender’s practices. One thing I think the professional marketer above is missing is that spamtraps are not really about scaring senders.

Spamtraps tell recipients and trap owners that some of the emails on a list are not going to people who asked for the mail. What’s mail a recipient didn’t ask for? Most people call it spam.

It’s important to realize that the traps are not the disease. Traps are the symptom. I’ve already mentioned that it’s sometimes difficult for senders to accept that their mail is unsolicited (or forgettable).

Traps are relevant, because if there are spamtraps on a list, then some part of your list is not who the sender thinks it is. Some of that mail is going to people who think it is spam. Mail sent to spamtraps belies the statement “we don’t sent spam.”

The other problem is that typos happen by real people signing up for mail they want. Because MAPS is using typo domains to drive listings, they’re going to see a lot of mail from companies that are doing single opt-in. I realize that there are problems with single opt-in mail, but the problems depends on a lot of factors. Not all single opt-in lists are full of traps and spam and bad data.

In fact, one ESP has a customer with a list of more than 50 million single opt-in email addresses. This sender mails extremely heavily, and yet sees little to no blocking by public or private blocklists.

Trend/MAPS policy is singling out senders that are sending mail people signed up to receive. We know for sure that hard core spammers spend a lot of time and money to identify spamtraps. The typo traps that Trend/MAPS use are pretty easy to find and I have no doubt that the real, problematic spammers are pulling traps out of their lists. Legitimate senders, particularly the ESPs, aren’t going to do that. As one ESP rep commented on yesterday’s post:

I work for an ESP and we don’t suppress domains like this, based on the theory that if a client is hitting spamtraps, we want to know so we can sanction or terminate them. But if Trend are acting in bad faith here, I guess my best bet is just to suppress any domain of theirs I can find (and it took about 30 seconds to find 2700 of them).   Another Anon

That’s a sentiment I heard over and over again from companies listed by Trend/MAPS. The companies are happy to force their customers to clean up their acts.  They want reports of bad behaviour by customers, but Trend/MAPS policy of forcing confirmations is taking a sledgehammer to kill a fly.

I think we have a reputation of being a bit harsh on customers, and we’re honestly a little proud of that. But I’m most proud of the fact that we are always fair and honest, even with the bad people.

We tell people what they need to change. The bad people who won’t take our advice are easy to kick out after that.

In this particular situation, we don’t have any advice to give. We don’t have a way to tell people “go do this.” Because it would be a lie. “Go remove inactives” won’t help. “Go re-confirm inactives” won’t help. Even “Go use double opt-in” won’t help if MAPS is clicking and opening everything.

And because MAPS is who they are, we can’t provide a lot of detail to customers, either.  An ESP Executive

COI is a tool. It is occasionally a good tool for keeping lists clean. But I’ve worked with dozens of senders over the year that aren’t using COI and are still keeping their lists clean because they have other processes in place to do so.

One common thread is that the ESP customers being listed aren’t the sort of sender who you’d expect to be a significant source of abuse. Real companies, gathering addresses from signup forms on their website. Not spammers who buy lists, or who harvest addresses, or who are generating high levels of complaints – rather legitimate senders who are, at worst, being a bit sloppy with their data management. When Trend blacklist an IP address due to a spamtrap hit from one of these customers the actions they are demanding before delisting seem out of proportion to the actual level of abuse seen – often requiring that the ESP terminate the customer or have the customer reconfirm the entire list.

“Reconfirming” means sending an opt-in challenge to every existing subscriber, and dropping any subscriber who doesn’t click on the confirmation link. It’s a very blunt tool. It will annoy the existing recipients and will usually lead to a lot of otherwise happy, engaged subscribers being removed from the mailing list. While reconfirmation can be a useful tool in cleaning up senders who have serious data integrity problems, it’s an overreaction in the case of a sender who doesn’t have any serious problems. “Proportionate punishment” issues aside, it often won’t do anything to improve the state of the email ecosystem. Rather than staying with their current ESP and doing some data hygiene work to fix their real problems, if any, they’re more likely to just move elsewhere. The ESP loses a customer, the sender keeps sending the same email.

If this were all that was going on, it would just mean that the MAPS blacklists are likely to block mail from senders who are sending mostly wanted email.

It’s worse than that, though.

The other thread is that we’re being told that Trend/MAPS are blocking IP addresses that only send confirmed, closed-loop opt-in email, due to spamtrap hits – and they’re not doing so accidentally, as they’re not removing those listings when told that those addresses only emit COI email. That’s something it’s hard to believe a serious blacklist would do, so we decided to dig down and look at what’s going on.

Trend/MAPS have registered upwards of 5,000 domains for use as spamtraps. Some of them are the sort of “fake” domain that people enter into a web form when they want a fake email address (“fakeaddressforyourlist.com”, “nonofyourbussiness.com”, “noneatall.com”). Some of them are the sort of domains that people will accidentally typo when entering an email address (“netvigattor.com”, “lettterbox.com”, “ahoo.es”). Some of them look like they were created automatically by flaky software or were taken from people obfuscating their email addresses to avoid spam (“notmenetvigator.com”, “nofuckinspamhotmail.com”, “nospamsprintnet.com”). And some are real domains that were used for real websites and email in the past, then acquired by Trend/MAPS (“networkembroidery.com”, “omeganetworking.com”, “sheratonforms.com”). And some are just inscrutable (“5b727e6575b89c827e8c9756076e9163.com” – it’s probably an MD5 hash of something, and is exactly the sort of domain you’d use when you wanted to be able to prove ownership after the fact, by knowing what it’s an MD5 hash of).

Some of these are good traps for detecting mail sent to old lists, but many of them (typos, fake addresses) are good traps for detecting mail sent to email addresses entered into web forms – in other words, for the sort of mail typically sent by opt-in mailers.

How are they listing sources of pure COI email, though? That’s simple – Trend/MAPS are taking email sent to the trap domains they own, then they’re clicking on the confirmation links in the email.

Yes. Really.

So if someone typos their email address in your signup form (“steve@netvigattor.com” instead of “steve@netvigator.com”) you’ll send a confirmation email to that address. Trend/MAPS will get that misdirected email, and may click on the confirmation link, and then you’ll “know” that it’s a legitimate, confirmed signup – because Trend/MAPS did confirm they wanted the email. Then at some later date, you’ll end up being blacklisted for sending that 100% COI email to a “MAPS spamtrap”. Then Trend/MAPS require you to reconfirm your entire list to get removed from their blacklist – despite the fact that it’s already COI email, and risking that Trend/MAPS may click on the confirmation links in that reconfirmation run, and blacklist you again based on the same “spamtrap hit” in the future.

We have been in a pretty lengthy back and forth with maps. Its just a disaster all around. We cleaned up around 200+ accounts, but they are still seeing trap hits. I finally got fed up and we just asked them outright “we cleaned up 200+ customers lists, and are still hitting traps? any chance you guys are clicking links?”. At this point they have a substantial amount of our IP space listed and are just making this painful. They haven’t had time to respond to our question, but at this point maps seems to be the new SORBS.An ESP’s take on the issue

We (Word to the Wise) aren’t an ESP – if we were then the risk of damage to our business due to publicly criticizing a blacklist would mean we wouldn’t be able to do it – so we don’t have first-hand experience of this behaviour. We have been told by six ESPs and an infrastructure company that Trend/MAPS has ongoing issues with inaccurate listings. Four of them have said that Trend/MAPS is clicking on links in email they’re sending, in some cases confirmation links. We’ve been provided data, including web access logs showing clicks on confirmation links in email sent to “trap” domains registered by Trend from anonymous Taiwanese consumer IP addresses. Many of the “trap” domains are registered by a Director of “Core Tech” at Trend Micro, at a Taiwanese address.

These email addresses were confirmed over the past several years, and have been used to justify aggressive blacklisting of ESPs since. MAPS representatives also confirmed to two ESP representatives that they did sometimes click on links in email sent to their trap addresses during investigations – and that matches data provided to us by another ESP that suggests Trend/MAPS will sometimes go through and click on many of the links in a batch of emails, possibly including any confirmation or reconfirmation links in those emails.

So, it seems that the Trend/MAPS blacklists are being run in a way that will sometimes blacklist sources of 100% COI wanted email, as well as sources of likely wanted email that’s not entirely COI. Conversely, it’s pretty easy to identify or block the trap domains they’re using (a simple google search will find thousands of them, and null-routing the five or so MXes they use would block all email to them) so any moderately smart spammer could easily avoid being listed by them. That suggests the data quality is probably poor.

It’s even worse than that, though.

Trend/MAPS don’t only run their own spamtrap domains. They also are fed data by spamtraps run by consumer ISPs, including Comcast. There’s data from the ESPs we’ve been talking to that show that senders that have been blacklisted by Trend/MAPS for “spamtrap hits” are sending email to @comcast.net addresses that had previously been confirmed by the same anonymous Taiwanese consumer IP address as was found clicking on confirmation links. So it’s likely that Trend/MAPS habit of clicking confirmation links in mail sent to “spamtraps” is poisoning ISPs independent spamtrap data, as well as their own published blacklists.

ESP representatives have been asking Trend Micro about these issues for months. On Wednesday we invited a MAPS rep to comment on the issue as we were planning on writing about it, but didn’t hear anything back beyond a request for specific examples. We declined to provide that for several reasons – it’s not our data to share, doing so would reveal which ESPs provided it to us, and it’s all been provided to Trend/MAPS by the ESPs concerned so they already have the data and are aware of the issues.

Trend/MAPS are tainting the spamtraps they use, by setting them up such that they’re likely to catch sources of mostly wanted email, including sources of 100% COI email. If they were doing that as part of a survey or research project, that would be OK, though the data would likely not be of much value. Instead, though, they’re accusing the senders of this mail of spamming, listing them on their blacklist and making unreasonable demands of the senders before they’ll remove their listing. As MAPS are also selling this data to large US consumer ISPs who use it to block email, the senders don’t have much choice but to comply with those unreasonable demands. (Update 8/9/11: A sender who was listed by MAPS in the last few days is seeing inbox delivery at the major US ISPs we believed were Trend/MAPS customers. It appears that our data on MAPS usage is out of date.) I also wonder how accurate Trend/MAPS are in how they represent their spam filtering services and blacklist data to those ISPs who use them – I doubt those ISPs are intending to buy a blacklist service that blocks wanted, COI email.

“I thought spamtraps were addresses that were valid and now aren’t.”

“I thought spamtraps were addresses created to catch spammers.”

There is a lot of “I thought…” about spamtraps. Most of the theories are accurate but limited. Like the blind men and the elephant, they catch the parts but not the whole of spamtraps.

When I first started out with email and spam, there was an easy definition of spamtrap. A spamtrap was an address that was never used but still received mail. By definition these addresses were never handed out, advertised or even used by a human. The only mail sent to that address was spam.

As spam filters became more sophisticated, other types of email addresses started being referred to as spam traps. The meaning of spam trap started to evolve into referencing an address that received all, or mostly all, spam.

This means that not all spam traps are created equal. Different kinds of traps tell you different information. This isn’t a problem as long as the people maintaining the traps understand the data they’re gathering. It also means that people dealing with blocking based on traps need to understand what kind of trap caused the block.

I’ve come up with a number of categories of spamtraps. This is not intended to be an exhaustive list. Also, there are overlaps in some categories. But this gives you an idea of the different sorts of traps in widespread use.

Classic spamtraps

Classic spamtraps are email addresses that were never assigned to a user but started receiving email.  In some cases, these are addresses at domains that accept mail to any address. In other cases, the domain owner will look through rejection logs, identify rejected addresses and then enable those addresses.

These traps tell the trap owner that the sender is randomly creating addresses or buying lists from someone who is. These are useful for identifying sources that are sending mail without permission.

There is a subset of classic traps that is the result of actual users submitting addresses they don’t own. Occasionally people sign up at various websites and use email addresses that they don’t own. One example is cute.net. People are constantly signing up for things with addresses at cute.net. But they don’t actually have an address at cute.net. To the domain owner, the mail is total spam and is indistinguishable from spammer created addresses.

Likewise, legitimate users might typo their own address while signing up for mail. Sometimes these typos find another user bob213 instead of bob123, but sometimes they will end up hitting addresses that are currently or will be spamtraps. To the domain owner, this is spam. Depending on the policies of the trap owner, these addresses may or may not trigger blocking.

Seeded traps

Seeded traps are email addresses that are created and seeded in various places online. Typically they are hidden on websites or sometimes dropped into unsubscribe forms.

These traps tell the trap owner that the sender is either scraping addresses or is buying lists from someone who is scraping addresses. These are good for identifying sources that are sending mail without permission, and those who are not honoring unsubscribe requests.

Message-id traps

Many address scrapers look for any string with an @ sign in it. Running scrapers over a websearch or usenet search will find valid addresses as well as message IDs. Some viruses will also scrape addresses, including message IDs, off machines they infect.

These traps tell the trap owner that the sender is scraping addresses or buying lists from someone who is. These types of addresses are almost never actually input into forms, so they make good “pure spam” traps.

Typo domain traps

These are traps at domains that are very similar to common domains, yaaho.com or ynail.com.

Mail to these traps tells the trap owner that the sender is trying to send mail to real people. Typically, these are not traps that are pure spam and in fact can contain a lot of real mail. Users frequently typo domains when sending mail, particularly if they are not using an address book.

These kinds of traps are often problematic when trying to run a blocklist. One trap driven blocklist told me about one of his typo domains, “I registered [a typo domain recommended by another blocklist], and it gets tons of mail. Unfortunately, it’s not all spam. It’s a firehose of personal correspondence between webmails and ISPs. It turned out to be very hard to separate that from any real spam and as a result, I ended up not using the domain to feed into my blacklist.”

Dead address traps

Dead address traps are once valid email addresses that are turned off. All mail to these addresses is rejected for some period of time, often 12 months or more. After consistently rejecting mail, the addresses are turned back on as spamtraps.

These are the type of traps made famous by Hotmail and are what most people seem to think about when they think spamtraps.  It’s not unreasonable as these are in use at major ISPs. These traps, though, mostly tell the trap owner that the sender has poor practices. Senders that are not purchasing addresses and who are removing bounces should not hit these traps.

There are some problems with dead address traps, though. These were valid addresses at some point, and some old correspondents may try and mail them. One person from a major ISP told me they tried to create these kinds of traps. The ISP spent 18 or so months “conditioning” the traps. First they rejected mail to the traps, then they monitored them, unsubscribing from commercial mail and notifying correspondents that the addresses were dead. Eventually, they abandoned the traps as too noisy to be useful.

Dead domain traps

Trap owners purchase expired domains and collect mail that comes into them. In many cases, these domains are turned off for a period of time, either rejecting mail or not resolving in DNS.

Dead domain traps are similar to dead address traps. Trap owners buy domains that have recently expired and turn them into spamtraps. Responsible trap owners will reject all mail to the domain for a significant period of time, to let real mail fall off.

Like the dead address traps, these traps may be too noisy to be used as a pure spamtrap.

Live traps

These are email addresses belonging to a real user. They are used for real mail, but the owners use the unsolicited mail coming into those addresses to make blocking decisions.

I have a number of these types of addresses. I use the addresses for one to one mail, but never use them to sign up for commercial mail. If I get any commercial mail at all, it’s spam by definition. The usefulness of these traps to drive blocks depends on the integrity of the person running them. There are people who I trust implicitly to only block mail they didn’t sign up for.

Domain registration addresses

Registration addresses are a special case of live traps. These addresses, published in whois records,  are frequently harvested and mailed.

Domain registration addresses are an interesting form of live traps. These addresses are frequently harvested and sold to unsuspecting business owners as “targeted business domains.” But any of us who own domains can tell you that not every domain is a business domain. Even if it is a business domain, mail to the registration address is still spam. All of us who have addresses on domain registrations can tell you that we get a lot of unsolicited, un-targeted crap to those addresses.

Investigative traps

These are email addresses created and submitted to senders. The goal of the trap is not to catch the sender doing anything bad, but to monitor the sender’s traffic. These traps can be used to catch addresses being stolen or sold. Some blocklists will also use these addresses to confirm that a sender is using confirmation on their list.

These are not traps that are necessarily useful for driving blocklists, but they are the sorts of addresses that are useful for monitoring ongoing behaviour of a sender.

Investigative traps can also be used to identify problem vendors. A few years ago I was working with a company doing confirmed co-reg. I signed up to their list with an investigative trap. Before I even received the confirmation message, I started receiving unexpected email to that address. Working with my client, we discovered that one of their vendors was siphoning off email addresses. That address was never confirmed with my customer, but is currently one of my largest spamtrap feeds.

Each kind of spamtrap tells the trap owner that a sender is mailing people who never asked to receive a mail. However, not every piece of mail received at a trap is spam. Not every piece of spam received at a trap is created equal. Each different kind of trap tells you something different about a sender and how they acquire email addresses.

The critical part of using spamtraps to publish blocklists is the integrity and trustworthiness of the trap maintainers. Most every trap out there could, conceivably, be the recipient of legitimate email. Some trap types have a higher probability of receiving legitimate mail than others. It’s highly unlikely someone is going to typo a message ID into a form. But it is quite likely that bob@cox.com might accidentally type bob@cix.com into a form.

Spamtraps are only as useful as their owners are honest.

Spamtraps are very simply unused addresses that receive spam. They come from a number of places, but the most common spamtraps can be classified in a few ways.

• Addresses that used to belong to someone and subsequently abandoned. This is where a lot of spamtraps at major ISPs come from.
• Addresses that were never assigned to anyone, but they just started receiving spam one day. These are frequently used to drive filtering.
• Addresses that were created and put on websites to track harvesters and web scrapers.  These addresses are frequently used to drive filters and track spammers.

Addresses that belonged to someone and were abandoned are usually “turned off” for a period of time between abandonment and re-purposing as a spam trap. They may return a 550 “user unknown” to any sender, or in some cases the entire domain will have no working mailserver. There are no hard and fast rules for how long the addresses are left unused, but most professionals leave them off for at least a year.

Addresses that were never assigned to anyone are not as common as they used to be. It used to be that some small or mid-size domain owners would turn on their SMTP server to accept all email to any address at that domain, existing or not. Mail to addresses that were not associated with a user would be stored. As the volumes of random mail increased, the spamtraps were used to drive filtering and blocking decisions. This is not as common now because the sheer volume of spam can create bandwidth and storage problems for domain owners.

Addresses that were seeded on websites, or on Usenet, are used for a number of purposes. These addresses often wind up on lists because someone has purchased addresses.

Spamtraps on a mailing list or in a database is a sign that there is some problem with the address acquisition process. As a result, the solution to spamtraps on a list is never just remove the available spamtraps. Instead, you need to figure out what broke and correct the underlying issues.

While I don’t have any actual numbers for how many people lie in forms, there was a slashdot poll today that asked readers “How truthful are you when creating web accounts?”. The answer seems to be “not very” at least for the self-selected respondents.

Slashdot Poll: 4196 total respondents

This is how spamtraps get on lists when the lists aren’t purchased. People who don’t trust your company with their data give fake data. Sometimes the data is easy to tell is faked “joebob@home.com” is clearly not a valid email address, neither is abcd@abcd.com or none@none.com. Even something like bill@microsoft or jobs@apple or obama@whitehouse can reasonably be filtered out. But there are a lot of other addresses that are handed over which aren’t obviously spamtraps. Some of them are handed over often enough that they turn into spamtraps, though. I once met the guy who owned someone.com and the amount of random spam he got from Legitimate! We never Buy Lists! companies was incredible.

Companies finding themselves with ongoing spamtrap problems when they are only collecting data through their own websites need to take a step back and look at their overall process. Often there are minor changes that can be made to lower the amount of invalid information submitted. Sometimes, though, there needs to be more aggressive data verification as part of the subscription or signup process.

We have helped a number of companies improve their signup processes. Those who implement our suggestions see improved delivery and fewer blocks as well as a more engaged and profitable audience.