PostFix can receive but can not send emails

[cjsdfw]

Hi everyone,

I spent all day trying to configure a system properly but still have some problems with Postfix configuration, at least I think so since I can not recive emails. My objective is to setup a virtual server under Virtualmin where the domain name is hosted by dyndns.org.

The website hosting is working fine so I move to the next step: configure Postfix.

• Configure hostname in dyndns
• Configure MX records in dyndns
• configure port forwarding on my router
• enabled SMTP port 587 in Postfix (Port 25 is blocked)

I can receive internal and external emails but I can only send emails internally. Whenever I send emails to an external address I get a connection timeout message (see log sample below).

System Info:

• Ubuntu 8.04 TLS
• Webmin 1.480
• Virtualmin 3.73 GPL

By the way, can anyone tell me how a sending mail server know which port to send emails to? Like in my case I am using port 587 and hotmail seems to know what to use but as you can see from the mail.log below my system is sending to port 25 all the time and at least in my other server (cjsdfw.com) I am using port 587 as well and not 25.

Any suggestion would help!
Thanks

Sep 28 23:49:38 cjsdfw postfix/smtp[7158]: 674A83D417A: to=<csanchez@cjsdfw.com>, relay=none, delay=1824, delays=1794/0.01/30/0, dsn=4.4.1, status=deferred (connect to mail.cjsdfw.com[69.199.29.26]:25: Connection timed out)
Sep 28 23:50:08 cjsdfw postfix/smtp[7159]: connect to mx1.hotmail.com[65.55.92.136]:25: Connection timed out
Sep 28 23:50:38 cjsdfw postfix/smtp[7159]: connect to mx4.hotmail.com[65.55.37.88]:25: Connection timed out
Sep 28 23:51:08 cjsdfw postfix/smtp[7159]: connect to mx1.hotmail.com[65.55.37.88]:25: Connection timed out
Sep 28 23:51:38 cjsdfw postfix/smtp[7159]: connect to mx3.hotmail.com[65.55.92.152]:25: Connection timed out
Sep 28 23:51:38 cjsdfw postfix/smtp[7159]: 674A83D417A: to=<cjsdfw@hotmail.com>, relay=none, delay=1944, delays=1794/0.01/150/0, dsn=4.4.1, status=deferred (connect to mx3.hotmail.com[65.55.92.152]:25: Connection timed out)
Sep 28 23:54:08 cjsdfw postfix/qmgr[5735]: 53E1B3D417E: from=<railsapps@cjsrails.dyndns.org>, size=683, nrcpt=1 (queue active)
Sep 28 23:54:38 cjsdfw postfix/smtp[7200]: connect to mail.cjsdfw.com[69.199.29.26]:25: Connection timed out
Sep 28 23:54:38 cjsdfw postfix/smtp[7200]: 53E1B3D417E: to=<csanchez@cjsdfw.com>, relay=none, delay=1099, delays=1069/0.01/30/0, dsn=4.4.1, status=deferred (connect to mail.cjsdfw.com[69.199.29.26]:25: Connection timed out)
Sep 29 00:14:08 cjsdfw postfix/qmgr[5735]: 53E1B3D417E: from=<railsapps@cjsrails.dyndns.org>, size=683, nrcpt=1 (queue active)
Sep 29 00:14:38 cjsdfw postfix/smtp[7471]: connect to mail.cjsdfw.com[69.199.29.26]:25: Connection timed out
Sep 29 00:14:38 cjsdfw postfix/smtp[7471]: 53E1B3D417E: to=<csanchez@cjsdfw.com>, relay=none, delay=2299, delays=2269/0.01/30/0, dsn=4.4.1, status=deferred (connect to mail.cjsdfw.com[69.199.29.26]:25: Connection timed out)