Hello!
I've spent a long time googling for an answer--no result so far. What I'm looking for is not necessarily a How-To, but just an answer and a shove in the right direction...
I would love (LOVE!) to enable users on my mail server to have e-mail addresses in the nice and memorable
user@domain.tld format, especially since I'm hosting several virtual domains on the box. I'm using Sendmail, Dovecot and Cyrus-SASL which all talk together nicely. Sendmail dutifully receives e-mail for all domains and puts them into the right places, even for user accounts whose names are of
user@domain.tld format. Dovecot provides them nicely through POP and IMAP. Dovecot lets me log in with a u@d.t username without problems.
The problem: Sendmail doesn't do too well with logins from e-mail clients using the account name format I'd like. If I telnet in and use AUTH LOGIN to log in as
user@domain.tld with the right password (both base64-encoded), authentication fails. Authentication succeeds when I log in as user@domain.tld@domain.tld, which makes me think Sendmail rips off the user name's host information at the last @ sign and only then passes on the information to saslauthd.
I've looked through the Sendmail documentation and tried out all configuration options I could find... testsaslauthd works fine with
user@domain.tld account names.
So, to make a long spiel very short: does anyone know if Sendmail uses a rewrite rule to process the user name passed with AUTH? And/or any way I could turn off Sendmail's butchering of user names during the authentication process? I couldn't find anything so far, so a pointer to the right place would be very welcome.

(I don't really want to tinker with the source code if not necessary, since I haven't been able to compile Sendmail with SASL support myself in all my attempts over the last few months...)
Thanks in advance!
Nadim