[tlug] Email forwarding

[Josh Glover <jmglov@example.com>]

Hi folks!

Long time lurker, first time (in a long time) poster. ;)

I have a query that the Googles and Ducks Duck Go of the world haven't been able to answer, but I have faith that the TLUG hive mind will be much more effective.

How in the world does email forwarding work? I recently pointed my domain MX records away from a friend's mailserver and onto my own ramshackle setup, [1] which forwards my email to a Gmail address. However, in order to deliver mail to my Gmail address, I have to change the sender address to the target Gmail address (which makes sense from a spam prevention point of view). What I'd like to do instead is do mailserver-to-mailserver forwarding so that I can preserve the original sender address, but I haven't yet figured out how to do that.

I've come across things like SRS, which seems to be part of the puzzle, but I'm still missing a few pieces down the back of the sofa or something, and can't assemble the whole thing.

Would anyone be so kind as to point me in the right direction?

Cheers,
Josh

[1] AWS Simple Email Service writing to an S3 bucket and a Lambda function that picks up the mail and sends it on using SMTP to mail.google.com.