I’ve been using qmail as my MTA for as long as I can remember. The feature I like most is being able to have one-off email addresses I can use across the web that can easily be disabled if I start getting spammed.

For folks who aren’t familiar with qmail, that means I can set up a prefix foo with the extension – and have email sent to foo-anytext@mydomain.com without having to reconfigure the server every time I want to create a new temporary email address.

At some point, that address will start getting spam. The bonus is that by using an extension that identifies the site where I used it, I immediately know where the leak started. When the spam shows up, I create a dot-qmail file to bounce email to that address. Over the years, I’ve accumulated a lot of dot-qmail files, so I’ve started using soft-links to manage them. On my server, I set up three dot-qmail files for my account:

.qmail-default controls normal delivery:

./Maildir/

.qmail-bounce will bounce an email:

|/var/qmail/bin/bouncesaying 'Mail is no longer accepted at this address.'

.qmail-bounce-and-deliver will bounce an email as far as the sender is concerned, but the email will still be delivered. This gives me time to slowly retire an email address that may still occasionally receive legitimate email:

|/var/qmail/bin/bouncesaying 'Mail is no longer accepted at this address.'

Once these three files are configured, I can immediately toggle delivery for a specific email address with a single command:

ln -s .qmail-bounce .qmail-anytext