We can do this by using 2 methods.
1- Login to Plesk >> Mail Server Settings >> Check “Enable message submission”.
Click OK.
Open that port 587 in csf or apf firewall.
You should now be able to send mail through your server on port 587
2- Make a copy of “smtp_psa” and rename that to “smtp_alternate”
Click OK.
Open that port 587 in csf or apf firewall.
You should now be able to send mail through your server on port 587
2- Make a copy of “smtp_psa” and rename that to “smtp_alternate”
cp -ar /etc/xinetd.d/smtp_psa /etc/xinetd.d/smtp_alternate
Insert the following on top :
service = smtp_alternate(Should be the same name as the file created) type = UNLISTED port = 2525
So that file should look like :
cat /etc/xinetd.d/smtp_alternate
service smtp
{service = smtp_alternate
type = UNLISTED
port = 2525
socket_type= stream
protocol= tcp
wait= no
disable= no
user= root
instances= UNLIMITED
env= SMTPAUTH=1
server= /var/qmail/bin/tcp-env
server_args= -Rt0 /var/qmail/bin/relaylock /var/qmail/bin/qmail-smtpd /var/qmail/bin/smtp_auth /var/qmail/bin/true /var/qmail/bin/cmd5checkpw /var/qmail/bin/true}Done.
If you want to add an alternate port on cPanel you can check our article on Open Alternative SMTP Port on a cPanel server