Hello sir @ShajalSaimon , I know how to setup outgoing mail server for 1 user. I want to know how to setup mail server for multiple users. consider user A and user B of same database , if user A sent a mail to a client then mail id of sender will be user A, and user B sent a mail to client then the sender mail will be user B

For setup user wise outgoing mail server you can use this module: https://apps.odoo.com/apps/modules/14.0/fl_outgoing_mail_server_user/