use the mailertable add to your /etc/mail/mailertable
domain_name smtp[123.123.123.123:2525]
Then run
make -C /etc/mail
Sendmail - use custom port for specific domains
use the mailertable add to your /etc/mail/mailertable
domain_name smtp[123.123.123.123:2525]
Then run
make -C /etc/mail