I am still fighting a battle to get Roundcube to send emails on port 587. My setup is a Debian Lenny server configured using the Perfect Server tutorial here with ISPConfig3. In the tutorial, Squirrelmail is installed. I had successfully configured Squirrelmail to send emails on port 587. When I ran into problems with Roundcube, I decided to back up and confirm Squirrelmail was still working. It seems after the recent upgrade, the Squirrelmail settings reverted to using port 25. Perhaps this was part of the reconfiguration of services done as part of the ISPConfig3 upgrade to the most recent build. Anyhow, I changed the SMTP port in the Squirrelmail conf.pl file back to port 587 and now I get the following error when trying to send emails from Squirrelmail. Code: 530 5.7.0 Must issue a STARTTLS command first I have tried a variety of settings, but I can't get email to go out unless the port is set to 25.