We see some typo domains in our mail queue from time to time and I have been thinking of using our internal DNS server to correct these people's mistakes.
Some examples from the current mail queue:
g-mail.com hotail.com hotmai.com hotmaiil.com hotmal.com htomail.com rediffmai.com yahii.com
The above domains do not have MX records but it's easy to see what the user meant when they typed it in.
The emails in question are often signup confirmation emails so the user can't login and fix their own email address and running a cron job that fixes it in the database won't send out the confirmation email again.
Setting our internal DNS to resolve these MX lookups to the proper Hotmail, Gmail or Yahoo (or whatever) addresses would most likely result in the mails ending up in the correct inbox. A cron job could also correct their email address in the database.
The best solution would be to do the MX lookup in the signup/email verification code on the web server so we can give the user an error message while they're still on the site but I'm a sysadmin and I can't get the dev time approved for this.
Can anyone see any potential problems with redirecting typo emails using DNS ?
I thought of a problem that potentially scuttles this whole idea. Assuming we do correct the typo domains using DNS, when we connect to the target mail server we're going to (at some point) say:
And the Hotmail server is probably going to reject it because they don't accept email for hotmal.com and they don't relay mail for me. The problem is that we haven't fixed the address. All we have done is pointed our MTA at the correct server as if we had the correct address.
I also found this mailing list archive which has a different solution to the typo domains. It doesn't solve my problem with letting the users know but it does get the mails out of my mail queue very quickly.