[CentOS] Centos 4 / Postfix / SMTP

Mon May 9 12:29:20 UTC 2005
Nigel Kendrick <support-lists at petdoctors.co.uk>

I've just installed Centos 4 on an Acer G310 server - everything's gone well
except I'm not able to SMTP connect to my upstream mail server (I've
installed postfix + MailScanner) - I managed to find sort out the dovecot
side of things but SMTP remains quite silent - the maillog shows an
attempted connect but then a timeout:

May  9 13:08:45 woking postfix/smtp[7895]: deliver_request_final: send:
"connect to mailhost.zen.co.uk[212.23.3.98]: Connection timed out" -1

If I connect manually (telnet mailhost.zen.co.uk 25) nothing happens - no
response is shown and I presume if I left things for long enough I'd see a
timeout message? Here's the output from netstat -pant:

Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address               Foreign Address
State       PID/Program name   
tcp        0      0 0.0.0.0:32769               0.0.0.0:*
LISTEN      2048/rpc.statd      
tcp        0      0 0.0.0.0:111                 0.0.0.0:*
LISTEN      2028/portmap        
tcp        0      0 0.0.0.0:21                  0.0.0.0:*
LISTEN      2242/vsftpd         
tcp        0      0 127.0.0.1:631               0.0.0.0:*
LISTEN      2181/cupsd          
tcp        0      0 0.0.0.0:25                  0.0.0.0:*
LISTEN      5201/master         
tcp        0      1 192.168.101.11:32847        212.23.3.98:25
SYN_SENT    7930/telnet         
tcp        0      0 :::993                      :::*
LISTEN      3416/dovecot        
tcp        0      0 :::995                      :::*
LISTEN      3416/dovecot        
tcp        0      0 :::110                      :::*
LISTEN      3416/dovecot        
tcp        0      0 :::143                      :::*
LISTEN      3416/dovecot        
tcp        0      0 :::80                       :::*
LISTEN      2345/httpd          
tcp        0      0 :::22                       :::*
LISTEN      2217/sshd           
tcp        0      0 :::25                       :::*
LISTEN      5201/master         
tcp        0      0 :::443                      :::*
LISTEN      2345/httpd          
tcp        0      0 ::ffff:192.168.101.11:22    ::ffff:192.168.101.20:4450
ESTABLISHED 3319/0              
tcp        0    192 ::ffff:192.168.101.11:22    ::ffff:192.168.101.20:4758
ESTABLISHED 5724/1    

I notice that there's an attempt to make a connection but that's it - any
ideas what might be causing this - I'm not running a server-based firewall.

Over to you with thanks.

Nigel