Well, this is an opinion. Actually, with Stalwart Mail, it became far easier to maintain an IMAP service than using an extra container and forwarding email. It’s also more standard.
I just rebuilt my email infrastructure to discover, like @jeanas, that IMAP support is limited to GMail. Limiting IMAP to GMail is hindering the email federation. Please consider looking into solid IMAP implementation of Stalwart Mail.
Note that Stalwart Mail also support JMAP protocol, which might be more interesting for Discourse, if you want to avoid IMAP.
It is just an opinion, but being able to just configure Discourse to use an address is still easier than creating a new inbox and password for each group and category you want Discourse to handle.
I’m pretty sure that this is the way that incoming mail is handled by CDCK and communiteq (and most sites I set up or maintain). So it is “standard” for Discourse.
I’d lke that too. I’m pretty sure that it’s no longer possible to set up a new mailbox for gmail either. I don’t know if CDCK has stopped using IMAP/Gmail and just using a mail receiver or what. I haven’t noticed any traffic on that topic lately (and am too lazy to search for it now).
Yeah, CDCK switched to all-mail-receiver, all-the-time, around 7 years ago (based on the initial commit to the mail-receiver repo; I don’t recall whether we’d started using it internally before publishing it).
Given that Discourse just wants to get a copy of the email and never think about it again, IMAP (and, I presume, JMAP) are massive overkill. Appeals to “more standard” are swamped by “sucks less”, and hoo boy, does running Postfix in a container suck so very, very, very much less than configuring POP3 (or IMAP) mailboxes both at a mail provider and in Discourse.
Because Gmail is huge and totally different service where massive Google has different needs than any Discourse server. But I’m just guessing now, of course.