Sendmail With Virtusertable and usernames with @ format

Just a quick question, we have a sendmail server that hosts about 100 mail domains on it and its currently using the virtusertable (along with the aliases, local-host-names, and mailertable) to define who goes where and does what.  The way we have it set up is that if your a mailbox hosted on that server, you've got an actual system account (in this example, lets say "Joe").  so joe has a useraccount of "joe" with an email address of "" and virtusertable basically has the below line:                 joe

It routes to his mailbox locally and he logs in via POP3 and picks up the email and all is well with teh world.  Problem is since joe is a username on the system, if we get another client who wants to use the username of "joe" for his email as well (clients who migrate to us for instance and are set in their ways about thier email addresses and usernames), we cant do it because joe is already a user and attached to another domain.  I've seen other hosting companies segregate these usernames out somehow (i know plesk does it pretty seamlessly), so i was wondering what kind of a change would i have to make to our setup to make it so that i can have two joe's that go to different domains on this box without having a conflict.

any ideas
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Hmmmm.....add another IP address to the system, and bind a second sendmail to that IP address (and keep the first one bound to the first IP address), and give it responsibility for the other Domain. That's what comes to mind immediately, altho I have a nagging suspicion that local delivery remains problematic.

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It is possible to solve the local mail problem by additional localhost IP's, but this sort of solution becomes very unwieldly very quickly. And, inaddition to needing multiple Sendmail instances with their own mqueue * mail dirs you also have to have multiple instances of the IMAP/POP servers.

A better solution is a mail system that includes virtual domain support, such a Cyrus.
JaidenkellAuthor Commented:
so basically, sendmail doesn't support the ability to have segregated usernames?  also, i have a client who is migrating from a format that had thier whole email address as thier username (, but if i try to use this setup in redhat/sendmail, it obviously wont let you use a @ in a username.  any ideas on that one?

thanks for the help so far guys!
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no. "@" is an invalid character

There is a module for webmin (assuming you're using a supported OS: linux, *BSD etc) called virtualmail that does what you're looking accomplish.
The Cyrus IMAP implementation allows for mail accounts for the form when Virtual Domain support is enabled.
I dunno - points split?
Split, Flip a coin, draw name from hat

what ever you decide to do will be fine ;)

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