I searched on the forum - the question was raised here, but the answer was not clear -
https://community.sophos.com/utm-firewall/f/mail-protection-smtp-pop3-antispam-and-antivirus/48933/route-incoming-email-to-two-different-smtp-hosts
I have a slightly different situation. I have one old mail server the license is going to expire, and I need to manually migrate all 600 mailboxes to a new server (IMAP mailboxes), so I cannot do a cutoff migration, both servers will need to receive incoming emails during the migration period.
My question is if I add the new server in the Host List (see screenshot below), will incoming emails be delivered to both hosts in the list?
No, Johnny, this is not a function of the SMTP Proxy. Your old mail server should be able to provide this. Any luck with that?
Cheers - Bob