I am using Sendmail ver 18.104.22.168 on Red Hat Linux 7.3 in the gateway mode.Users dont have mailbox on this server , it only has alias and forwards mail to the exchange server.
My server accepts mail for 2 domains lets say abc.com & xyz.com and all users have aliases.
I have a specific requirement of forwarding one of the user's mail to another mail server.
For eg: email@example.com
wants to forward mails for this id to firstname.lastname@example.org
Alias file is not accepting two entries for user1 and it doesnt forward to the external id if i give explicitly agaist the warnings.