I installed Dovecot on my fedora core 6 system as a POP server. My goal is to be able to receive emails @mydomain.com. Right now if I send an email to user@mydomain.com the email bounces right back with the following information:

Your message cannot be delivered to the following recipients:

Recipient address: user@mydomain.com
Reason: Remote SMTP server has rejected address
Diagnostic code: smtp;550 User unknown
Remote system: dns;mx1.mailhop.org (TCP|10.23.32.29|51983|63.208.196.176|25) (mxin2.mailhop.org ESMTP Exim 4.63 Sat, 10 Mar 2007 21:34:19 -0500)

As you can see I'm using dyndns's relay service because my isp blocks port 25. So I have redirected to port 587 by making the changes in sendmail.mc to accept incomming connections on that port. I also openned port 587 on my router's firewall.

The user exists as a regular user on my linux system so I don't know why the message isn't being received. Any help would be appreciated.

Thanks

This may be a stupid question, but did you actually start the dovecot process (service dovecot start)? If it isn't running, you will get a response like that. If you want to check, at the command prompt type," ps -ef | grep dovecot". You should see some processes running other than the request you just asked for. if not, then type the start command as above. Try that and repost.

I found my problem, I had to remove authentication for my server. By replacing a lowercase "a" by uppercase A in sendmail.mc. Everything works great now.

Thanks for posting your solution -- it may help others.

which "a" did you change? I'm having the same issue and that seems to be the solution to my problem.