Problem with Postfix and SMTP port 25

[laidbackwebsage]

I followed the "Perfect Hardy Heron Ubuntu Server" step by step, but I am still unable to access my remote SMTP server from my desktop (i.e., I cannot send a test email using Thunderbird.)

The server resides on a VPS host, and I can send mail from the command line. However, I cannot connect to the SMTP server via Thunderbird, not can I telnet to port 25.

How do I:

Test if port 25 is open?
Open it safely if it isn't?
Change the port if my local ISP is blocking it?


Thanks!

Kevin J

[joel_griego]

If your server has local ip address for example 192.168.1.1 you can command to another local computer:
telnet 192.168.1.1 25

it should show the smtp greeting.

If your ISP is blocking port 25, maybe you can consider using submission port.


cheer,
Joel

[falko]

What's the output of netstat -tap? any errors in your mail log?

[laidbackwebsage]

Here's the output of sudo netstat -tap
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 localhost:mysql *:* LISTEN 7856/mysqld
tcp 0 0 *:www *:* LISTEN 9585/apache2
tcp 0 0 <FQDN> *:* LISTEN 7318/named
tcp 0 0 localhost:domain *:* LISTEN 7318/named
tcp 0 0 *:smtp *:* LISTEN 11732/master
tcp 0 0 localhost:953 *:* LISTEN 7318/named
tcp 0 0 *:https *:* LISTEN 9585/apache2
tcp6 0 0 [::]:imaps [::]:* LISTEN 9181/couriertcpd
tcp6 0 0 [::]:pop3s [::]:* LISTEN 9088/couriertcpd
tcp6 0 0 [::]:pop3 [::]:* LISTEN 9023/couriertcpd
tcp6 0 0 [::]:imap2 [::]:* LISTEN 9124/couriertcpd
tcp6 0 0 [::]:ftp [::]:* LISTEN 11019/proftpd: (acc
tcp6 0 0 [::]:domain [::]:* LISTEN 7318/named
tcp6 0 0 [::]:ssh [::]:* LISTEN 3487/sshd
tcp6 0 0 [::]:smtp [::]:* LISTEN 11732/master
tcp6 0 0 ::1%##########:953 [::]:* LISTEN 7318/named
tcp6 0 1200 <FQDN>:ssh ip###############:54923 ESTABLISHED 21688/sshd: ## [

"mail.err" is empty, and "mail.log" loks fine. Saw something in "mail.info", though; what does this mean?

Feb 18 20:26:30 mail imapd: chdir Maildir: No such file or directory

BTW, many thanks, All, for your assistance!

Kevin J

[falko]

Looks good.

Is there a firewall that is blocking port 25?

[laidbackwebsage]

How do I tell? :-P

(Thanks.)

Kevin J

[falko]

What's the output of iptables -L?

[laidbackwebsage]

Here it is; I haven't set up any rules, yet, evidently:

Chain INPUT (policy ACCEPT)
target prot opt source destination

Chain FORWARD (policy ACCEPT)
target prot opt source destination

Chain OUTPUT (policy ACCEPT)
target prot opt source destination

[falko]

Is the server located in a data center, or is it hosted on a DSL line or something similar? In the latter case, make sure that your ISP doesn't block port 25.

[laidbackwebsage]

It's a virtual server that I have complete control over, other than assigning the IP address.

I access the Internet via a high-speed connection through my cable company. At this point, I'm guessing they don't allow access to port 25 on any domain except their own.

How do I tweak my postfix settings to allow access on a differetn port, and what ports would be suggested?

Falko, thanks for your help; it is greatly appreciated.

Kevin J

[joel_griego]

You can use submission port. Just modify your master.cf.

Joel