Hello,

ISSUE:

when i setup Gmail to download e-mails also from my non-gmail mailboxes like [email protected] and want to use GMail to send out an e-mail on behalf of [email protected], then the recipient can see [email protected] in the e-mail source code (e-mail headers) and this is often unwanted i guess.

SOLUTION:

Here is what worked to remove my gmail address from headers: Gmail / Settings(Options) / Accounts & Import / Send mail/e-mail as: / Edit my third party mailbox / do NOT set it as an alias

Then from that time, e-mail headers not show my gmail address, "only" shows that the real sender was not me@hotmail, but gmail in general:

Received: from mail-qt0-f171.google.com ([209.85.216.171]:35731) by hotmail.smtpserver.here with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.89) (envelope-from <[email protected]>) id 1daViz-0006Kg-Bt for [email protected]; Fri, 11 Aug 2016 02:03:14 +0000
Received: by mail-qt0-f171.google.com with SMTP id p3so36757812qtg.2 for <[email protected]>
So it allowed me to send e-mail from Gmail on behalf of other non Gmail hosted mailboxes without recipients be able to see my Gmail address. Nice

PS: This does not seem to work when you are sending from [email protected] on behalf of [email protected], the [email protected] is still shown in headers :-/ workaround is to switch to me2 account to send out e-mail