I’m curious to hear what kind of workarounds everyone ended up with for this issue. I’m facing the same problem with our intranet Discourse which is running on a DNS name that doesn’t exist outside our corporate network, and it means all the image links in the emails Discourse sends are broken for mobile users without an active VPN connection.
The main annoyance is the lack of Discourse emoji, I am thinking a potential solution could be to rewrite them to Unicode emoji in email notifications?
Or perhaps to be able to define a separate discourse hostname to use inside HTML email, then we could have a static web facing server that hosts the emoji and avatar images. As a kludge, I am thinking of configuring a simple SMTP relay that rewrites the hostname before forwarding it to our Exchange server…
I don’t think I will be allowed to make the primary Discourse host face the open web unfortunately 