I'm not going to divulge the name of the software, but I will say that it is a very well known and well respected ECM application.

Nothing small time about it; a typical installation runs between $50k and $100k, some are much more.

The desktop client currently can only use MAPI compliant email, but I have found that since my original post, that the web client works just fine with Gmail.

The desktop client (or the old school term of "thick client", if you will), is in the process of ultimately being phased out. This is actually a very good thing, as there is no maintenance involved in making sure the users have the latest version, patch, etc...

The application itself is running on Server 2012, and all the users' desktops are on Windows 10 64 bit. The customer is using Gmail, without any additional client. They do have Outlook available, ( as they have MS Office), and IT will set up any user with Outlook / Gmail should they require it.

As the only PC I have access to is the Server 2012, I was hoping to be able to send from it if need be. I now know that I can use the web client if I have to.