Imap + sendmail bahavior

Jesper K. Pedersen jkp at
Fri Apr 29 13:37:33 EDT 2005

On Fri, 29 Apr 2005 10:18:21 -0400
"Fields, David" <David.Fields at> wrote:

> Hi,
> I'm relatively new to using/running an IMAP server, but so far, I like
> what I've seen from the Cyrus server.  I do have some strange behavior
> that is puzzling me though.  I'm running this on my home server and
> it's just for own personal use (I have my reasons), but I prefer using
> IMAP over POP3 because I have some software that allows my Outlook
> client and my Mutt client to share the same mailbox.  At home, I
> generally use Outlook (yeah, I know, it's full of bugs, but the
> interface still blows away pretty much everything else out there). 
> When I'm at work, or at home, I use mutt to read my mail when
> connection through my firewall.
> However, ever since I moved to using IMAP, any time anyone tries to
> deliver mail to mailboxes that don't exist on my mail server (and this
> happens a lot), the mail server tries to send a response mail message
> back to whoever it thinks sent the message.  With the way SPAM/Virus'
> work these days, that's not really a good thing to do.  I would like
> to prevent this from happening.
> My configuration was with an older version of the IMAP server software
> (not sure of the exact version since that machine died and I'm in the
> process of rebuilding a new machine).  I was using the latest version
> of sendmail, but I'm considering using Postfix on my new server.  If I
> remember right, this did not happen at all when I was using sendmail
> and POP3.  It only started happening after I moved to IMAP.  
> If anyone has seen anything like this and knows how to prevent this, I
> would appreciate any comments/suggestions you may have.

What you should do is have sendmail check the recipient when someone
tries to deliver mail. If the recipient doesnt exist you just let
sendmail deny forwarding it to Cyrus Imap.

This page should get you up and running in a very short time

Personally I use the mailertable solution to manage a couple of small
domains and I have had no problems with it.

Jesper K. Pedersen
Carpe Aptenodytes!
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