Realtime Address Verification
Catchall domains
Catchall domains accept any mail to any email address at that domain. They were quite common, particularly at smaller domains, a long time ago. For various reasons, most of them having to do with spammers, they’re less common now.
Most folks think catchall domains are only used for spamtraps. As a consequence, many of the address verification tools will filter out, or recommend filtering out, any address that goes to a catchall domain. They test this by trying to send emails to random addresses like sldqwhhxbe+ym7ajymw23gm0@clientspecific.domain.example.
But not all catchall domains are used for spamtraps. Every client here at WttW gets a domain assigned to them and those domains are catchalls. Emails to those domains go into a database for analysis. Clients (and I!) can create any LHS on the fly to test signups, look at mail flows. Having a catchall means we don’t have to actually configure any address so I can test multiple signups and encode the data about the signup in the to: address.
This works most of the time, at least until verification services mark those addresses as bad and they don’t get imported into the client’s processes. We have some workarounds, and can still get mail despite the services making assumptions.
Email verification services
Just yesterday a group of delivery folks were discussing email verification services over IRC. We were talking about the pros and cons, when we’d suggest using them, when we wouldn’t, which ones we’ve worked with and what our experiences have been. I’ve been contemplating writing up some of my thoughts about verification services but it’s a post I wanted to spend some time on to really address the good parts and the bad parts of verification services.
Today, Spamhaus beat me to the punch and posted a long article on how they view email verification services. (I know that some Spamhaus folks are part of that IRC channel, but I don’t think anyone was around for the discussion we had yesterday.)
It’s well worth a read for anyone who wants some insight into how email verification is viewed by Spamhaus. Their viewpoints are pretty consistent with what I’ve heard from various ISP representatives as well.
In terms of my own thoughts on verification services, I think it’s important to remember that the bulk of the verification services only verify that an address is deliverable. The services do not verify that the address belongs to the person who input it into a form. The services do not verify that an address matches a purchased profile. The services do not verify that the recipient wants email from the senders.
Some of the services claim they remove spamtraps, but their knowledge of spamtraps is limited. Yes, stick around this industry long enough and you’ll identify different spamtraps, and even spamtrap domains. I could probably rattle off a few dozen traps if pressed, but that’s not going to be enough to protect any sender from significant problems.
Some services can be used for real time verification, and that is a place where I think verification can be useful. But I also know there are a number of creative ways to do verification that also check things like permission and data validity.
From an ESP perspective, verification services remove bounces. This means that ESPs have less data to apply to compliance decisions. Bounce rate, particularly for new lists, tells the ESP a lot about the health of the mailing list. Without that, they are mostly relying on complaint data to determine if a customer is following the AUP.
Spamhaus talks about what practices verification services should adopt in order to be above board. They mention actions like clearly identifying their IPs and domains, not switching IPs to avoid blocks and not using dozens or hundreds of IPs. I fully support these recommendations.
Email verification services do provide some benefit to some senders. I can’t help feeling, though, that their main benefit is simply lowering bounce rates and not actually improving the quality of their customers’ signup processes.
Sending mail to the wrong person, part eleventy
Another person has written another blog post talking about their experiences with an email address a lot of people add to mailing lists without actually owning the email address. In this case the address isn’t a person’s name, but is rather just what happens when you type across rows on they keyboard.
These are similar suggestions to those I (and others) have made in the past. It all boils down to allow people who never signed up for your list, even if someone gave you their email address, to tell you ‘This isn’t me.” A simple link in the mail, and a process to stop all mail to that address (and confirm it is true if someone tries to give it to you again), will stop a lot of unwanted and unasked for email.
Verifying addresses after POS collection
Collecting email addresses at point of sale is a challenge. Some stores collect the addresses electronically, where the clerk or the customer types addresses directly into the register. Smaller stores, however, typically collect addresses on a sheet of paper at the cash register. Eventually someone takes the list and types it into whatever contact management system the store maintains.
There are all sorts of errors that can happen when someone types in an address, but those errors are only compounded when the addresses are written on a sheet of paper for later transcription. Not all of us have perfect, copperplate handwriting and many of us have barely legible scribbles. In one case I had a sender read the tag in my email address wrong causing all their mail to me to bounce.
One person found an interesting solution to the problem of illegible addresses: using Facebook’s lookup to clarify illegible addresses.
Email verification – what are we verifying
One of the ongoing discussions in the email space is the one about address verification. Multiple companies have sprung up to do “real time” email address verification. They ensure that addresses collected at the point of sale are valid.
But what does valid mean? In most of these contexts, valid means that the addresses don’t bounce and aren’t spam traps. And that is one part of validating email addresses.
That isn’t the only part, though. In my opinion, an even more important thing to validate is that the email address belongs to the person giving it to you. The Consumerist has had an ongoing series of articles discussing people getting mis-directed email from various companies.
Today the culprit is AT&T, who are sending a lot of personal information to an email address of someone totally unconnected to that account. There are a lot of big problems with this, and it’s not just in the realm of email delivery.
The biggest problem, as I see it, is that AT&T is exposing personally identifiable information (PII) to third parties. What’s even worse, though, is that AT&T has no process in place for the recipient to correct the issue. Even when notified of the problem, support can’t do anything to fix the problem.
What are you validating?
Al throws in his own two cents on the question of real time address validation.
Read MoreCan you verify email addresses in real time?
In a recent discussion about spamtraps and address lists and data collection a participant commented, “[E]very site should be utilizing a real-time email address hygiene and correction service on the front end.” He went on to explain that real time hygiene prevents undeliverable addresses and spamtraps and all sorts of list problems. I was skeptical to say the least.
Yes, there are APIs that can be queried at some of the larger ISPs to identify if an account name is taken, but this doesn’t mean that there is an associated email address. Yes, senders can do a real time SMTP transaction, but ISPs are quick to block SMTP transactions that quit before DATA.
I decided to check out one service to see how accurate it was. I’m somewhat lucky in that I created a username at Yahoo Groups over a dozen years ago but never activated the associated email address. This means that the account is shown as taken and no one else can register that address at Yahoo. But the address doesn’t accept any mail.