Can I use additional port other than port 25 for SMTP/ or change the SMTP port

[sunshine]

Choose any unused port and add it to the /etc/services file, for example:



smtp_alt 25025/tcp # new SMTP port

If you have 'xinetd' as super-server, make a copy of /etc/xinetd.d/smtp_psa to /etc/xinetd.d/smtp_psa_alt and correct service line within new file:

service smtp_alt

Restart xinetd '# /etc/init.d/xinetd restart' and SMTP connections will be accepted on the both standard and 25025 ports. You may also need to reconfigure Horde IMP (webmail) settings so it use alternative SMTP port too. This can be done in /etc/psa-horde/imp/servers.php file under smtpport parameter for both IMAP and POP3 servers.


In case if 'netd' super-server is used (Debian or FreeBSD), modify inetd.conf to enable additional SMTP port:

grep '^smtp ' /etc/inetd.conf | sed 's/^smtp/smtp_alt/' >> /etc/inetd.conf

and restart inetd.


If you wish to disable default (25) port at all and continue using alternate one only, please do not block 25 port at firewall and do not remove 'smtp_psa' service from xinetd/inetd but set default SMTP service be listened on 127.0.0.1 only by adding 'bind = 127.0.0.1' to /etc/xinetd.d/smtp_psa, otherwise SMTP service status will be displayed incorrectly in Plesk CP. Plesk determines SMTP service status by checking 25th port and the port number is hardcoded there.

:dancing:
Regards,
Sunshine

[BodShane]

Here is an handy solution to open ports on a Linux Operating System :

First, you will need to login as Root and type /usr/sbin/lokkit

Remember you need full SSH root access on the dedicated server or virtual private server.

From the menu, select custom. leave blank next to ethport or mark if you need to allow traffic. Then, mark all services which required remote access. Thereafter add additional ports by typing XX:tcp XX:udp ( xx : port number )

Save the configuration. That's all!