On Thu, 2 Apr 2020 at 17:33, Bill Cole <postfixlists-070...@billmail.scconsult.com> wrote: > > On 2 Apr 2020, at 2:55, Tessa Plum wrote: > > > Hello > > > > We can send email from any domain within gmail, setup it via gmail's > > smtp relay in web interface. > > > > My question is, won't this break something like SPF/DKIM for those > > external domains? > > Yes, but you should be able to fix SPF by including the GMail SPF > record. That assumes that you haver control over the domain's SPF TXT > record. > > DKIM is more complex. I don't believe GMail offers any solution, but > there should be something that paying GSuite customers can do, and > presumably that can be found through GSuite support channels.
The standard way to achieve what OP wants is to relay the outgoing emails from Gmail through your own mail server which can then add the appropriate DKIM header. This also makes it easy to meet SPF without having to include all Gmail SPF records in your domain's SPF. This works for free Gmail accounts.
