Port 25 Occupied

1. Edit the master configuration file of postfix using the following command:

vim /etc/postfix/master.cf

1. Locate the line that specifies port 25 and modify it to use a different port, such as 2525:

smtp            inet      n      -       n       -       -        smtpd

Change it to:

2525            inet      n      -       n       -       -        smtpd

1. Save the changes and exit the file.

2. Apply the modifications to postfix by restarting the service:

/etc/init.d/postfix restart