remote host unable to send to sendmail

[frankdw]

I just set up sendmail on openbsd, and I can send and receive email locally, and can send email to a remote host, but cannot receive email from a remote host. Email from a remote host fails with the error message "unable to make an smtp connection". NMap says that the SMTP port 25 is open. Any help would be appreciated.

 

[RhythmAce]

Look near the bottom of your sendmail.mc file for a line that starts with DAEMON_OPTIONS. If you see the ip 172.0.0.1, that means sendmail is only looking at the loopback device. Change the ip to your internet ip. Then run m4 to recompile sendmail.cf

 

[frankdw]

Thanks, I found the MTA and MSA DAEMON_OPTIONS you indicated, and changed the ip (from 0.0.0.0) to the mail ip, with no change. Any other thoughts? Thanks much.

 

[RhythmAce]

Hmmmm. Did you recompile sendmail.mc and restart sendmail afterwards? Sorry I can't think of anything right now but I seem to remember that Red Hat used to use a file that disabled inbound mail, telnet and ftp by default but for the life of me I can't remember what it was. Is there any chance your distro uses a file like that? I think it was in the /etc/ directory.

 

[frankdw]

Thanks again. I've done all that, and everything works except receiving mail from a remote host. I have a sendmail book that I am studying, which helps also. Also my ISP has been helping me look for any DNS and sendmail issues. Thanks.

 

[RhythmAce]

firewall?

 

[frankdw]

I use pf filtering, but it is passing port 25 unrestricted.

 

[fluffybunny]

How long ago did you register your DNS ? DNS takes time to propogate changes and your server may not be listed as yet.

Try to send an email using your ip address from another location like hotmail or something like that. Does the mail get through ? (ie. mail guest@xxx.xxx.xxx.xxx).

If the mail does go through, then it could be DNS that is the problem.

If this is not the case, try disabling your firewall and try again.

Regards.

 

[erchiu]

Try enable SMTP AUTH in sendmail.m4. Then from your email client such as outlook, set "My server requires Authetication".