Some months back I posted an article pertaining to SMTP connectivity problems users of Hostgator accounts may experience, resulting from network security measures applied by default to Hostgator shared hosting accounts.
I recently ran into a very similar problem with TMDHosting. Like with Hostgator, the problem manifested itself within SugarCRM through the inability to send email. Examination of the sugarcrm.log file revealed error messages indicating the connection to the SMTP server timed out.
As it turns out, TMDHosting also closes some ports for outgoing traffic on its shared hosting accounts. In this case in particular, the port in question was number 26. Thus, if you wish to use SugarCRM to connect to a server that is listening on port 26, you should first contact TMDHosting technical support and request that they open up outgoing traffic on that port for your account.