Msgtag

I presume that Secure Email inserts itself as a proxy, and alters the settings in the email clients so that the email is routed through the new proxy, which in turn adopts settins for the isp’s taken from the email clients. Is that right, and if so what happens if there is already a proxy in place, as where Msgtag (Message Tag) is already installed on the computer. Is it possible to check the settings adopted by Secure Email in respect of such matters as the name of the outgoing mail server, whether it requires authentication or a secure connection, and the correct port to use?