A mail session stops automatically when Adaptive Server shuts down. You also can explicitly stop an Adaptive Server mail session at any time with the xp_stopmail ESP.
For syntax and parameters for xp_startmail and xp_stopmail, see the Adaptive Server Reference Manual.
Stop the current Adaptive Server mail session with xp_stopmail before using xp_startmail to start another mail session for a different profile name. Until you stop the first session, the second session cannot access resources that are considered to be still in use by the first session.