Open the file master.cf available at the following path:

/opt/trend/imss/postfix/etc/postfix

Add the following line at the end:

587 inet n - n - 200 smtpd

Open then the port on the firewall:

/opt/TrendMicro/GoldenGate/bin/fwPortConf add tcp 587

Restart postfix with the following command line:

postfix restart