is it possible to use UCS mail with an external SMTP like microsoft xchange or google? if it is possible what is the tool for integrating the UCS mail server with the external SMTP.
It depends on what you want to do with the external SMTP.
As a first step I’d recommend to have a look at 13.7.1. Configuration of a relay host for sending the e-mails.
i want the external smtp to be able to relay mails to offsite users that might be working out of the office like staffs in sales and marketing department.
Thats what a relay would do. Did the linked documentation help?