Cleaning up years of sign-up form typos
How the list got this way
- Checkout and sign-up forms accepted anything shaped like an address, because a validation rule that rejects a real address costs a sale.
- Mobile keyboards and autocorrect produce a steady rate of transposed characters that nobody proofreads.
- People mistype the domain more often than the local part, and gmial, gmai and hotmial accumulate in every consumer list.
- Some typo domains are registered deliberately by operators who accept the mail, so the address resolves and the message goes to a stranger.
The confirmation email cannot correct the error that broke it
A mistyped address fails silently from the customer's side. They completed the form, saw the success screen, and now wait for a receipt or a confirmation that was posted to an address one character away from theirs.
From your side it is a bounce in a log nobody reads, attached to a customer who appears in the funnel as a drop-off. The two facts are never connected, and the person is usually gone before anyone looks.
Where the typo domain is registered and accepting, it is worse. There is no bounce at all, the message reaches somebody else's mailbox, and the receipt for your customer's order has been delivered to a stranger.
What a check removes, and what it leaves
Both columns matter. A verifier that only advertises the left one is describing half the job.
| Removed by checking | Still there afterwards |
|---|---|
| Addresses at domains that do not exist, which is where most typos land. | Recover the correct address. Knowing an address is wrong does not tell you what the customer meant to type. |
| Misspellings of the large consumer providers, which are common enough to be recognized on sight. | Detect a typo at a registered typo domain, which accepts the mail and looks entirely valid. |
| Syntax errors, including the missing @ and the stray space that a lenient form accepted. | Catch a valid address belonging to the wrong person, where someone typed a real address that is not theirs. |
| Rows that have been bouncing for years in a log nobody was reading. | Undo the lost order. This one is genuinely fixable only at the form. |
What to do instead
Verify at the form, with a suggestion rather than a block
Offer the correction and let the person confirm. Never reject an address outright on a non-answer, because blocking a real customer is worse than accepting a typo.
Set a short timeout and fail open
A form that waits on a verification API is a form that loses orders when the API is slow. Accept the address if the check has not answered quickly.
Read the bounce log against your sign-ups
Sign-ups that never received a confirmation are typos, and the pattern in them tells you which field on which device is producing them.
Ask again where the value justifies it
For an order or an account, a bounced confirmation is worth a second attempt through another channel. For a newsletter it is not.
Questions people ask
Can a verifier fix a mistyped email address?
It can tell you the address does not work and, where the domain is a near-miss for a common provider, suggest the likely intended spelling. It cannot know what the person meant, which is why the correction belongs on the form while they are still there.
Should a sign-up form block an address that fails verification?
No. Suggest a correction and let the person decide. A check that blocks on an ambiguous result will eventually turn away a real customer with an unusual but working address.
What happens if someone registers a typo domain?
The mail is accepted and delivered to whoever operates that domain. There is no bounce, your logs look clean, and your customer's confirmation went to a stranger. Catching it at the form is the only defense.
How many sign-ups are typos?
It varies with the form, the device mix and whether the field is confirmed. We have no measured figure of our own, and the number worth having is the one from your own bounce log.
Related list problems
Measure your own list before you clean it
100 free checks a month, no card. The rows we could not get an answer on come back labeled rather than guessed at, and we never bill for them.