smtp auth works from some locations and not others

[Vettezuki]

I have a co-located server running postfix as the mailer. I've configured postfix for SASL auth. It worked as I expected for a while. Then for no reason I've been able to detect, I was no longer able to send mail from home, but I still could from work. My guess is that postfix is somehow restricting attempted smtp connections from addresses it can't find a name for (like a typical home address). . . but allows smtp connections from major domains.

Any suggestions? If this seems plausible, where would this setting reside? The following is what I have at the end of my main.cf, which worked at one point.

smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
smtpd_sasl_local_domain = $myhostname
broken_sasl_auth_clients = yes

smtpd_recipient_restrictions =
permit_sasl_authenticated,
permit_mynetworks,
reject_unauth_destination

 

[hpg4815]

Hi,

What error messages are you getting?

can you telnet to port 25 from outside the network where the machine is residing?

 

[Vettezuki]

I'm embarassed to say I just thought of trying that last night and monitor tcpdump (new tool to me).

Nothing . . . not a single packet is even getting to the server. I'm going to call my ISP and ask if they're filtering port 25 to certain domains. This is looking more like the case at the moment. Thank you for your reply.

 

[Vettezuki]

Well, it seems that my ISP recently implemented a new policy of blocking all port 25 traffic except to their servers. I'm now using port 465 (smtps) with SSl and it is working. What a pain. I should have thought to see if any traffic was even reaching the server before checking the server's configuration. All is well now.