Internal email set-up

I'm feeling a little silly and I would appreciate some assistance.

We've been using SugarCRM since 2012 and we have a separate email server.  Most of the users have been on Outlook for their mail using the plug-in for archiving.  Some users have recently switched to Thunderbird.

The new (improved) email function in Release 7.10 is interesting, and I'm thinking we should switch to it.  I'm trying to set up an account to use the internal email without success.  When I try to set it up with SMTP Authentication I keep getting this error:

Error: Could not connect to the email server. Please make sure that email configuration has been setup correctly.

When I remove the SMTP Authentication, It saves but trying to send an email gives this error:

Error There was an internal server error. Please try again.

The main email configuration is set to allow users to use the server settings for the system account that sends SugarCRM notices.  I've verified that the SMTP server, the SSL security, and the port are the same as the Outlook clients.  

Will someone provide me with some direction?  Hopefully without increasing my feeling of being an idiot :-)