Did a fresh install of ZMC on a CentOS 5.x x64 machine. The FQDM is (fake) server.domain.com but I get mail to users@domain.com so on the install I set the domain name to domain.com. I left all other settings primarily at default to ensure everything worked before dealing with my gateway. However, I cant seem to send email from the web interface logged in as the admin user? But if I go to a shell, tail /var/log/maillog and run "mail -s 'test' admin@domain.com", or even "mail -s 'test' user@anotherdomain.com" it works fine? Just not from the web interface. It just times out, gives an error, nothing in /var/log/zimbra.log etc? Now I also have a gateway server and another internal SMTP server which does not require authentication but even if I put in any of these into the "Relay MTA for external delivery" field with a port, or leave it empty, or even use localhost and port, sending mail times out with no message other than "The server is slow to respond....". Any suggestions?