we have two groups which each have their own mail-adress for incomming mails.
Now I sent an email to group1@hostname.de and in CC to group2@hostname.de.
The mail showed right at the admin control center under /admin/email/received but onlygroup1 received it.
I repeated this with group1 in CC and the mail only showed up in group2s inbox.
Even if I do not use CC and send the mail to group1 and group2 simultaneously, only group1 received it.
I’m pretty sure we only post to the group indicated by the first valid-looking e-mail address we find. Arguably, for caegories at least, this is correct behaviour, because Discourse doesn’t have the concept of “a single message which exists in multiple categories”, and while it might be annoying to have your carefully crafted missive only show up in one of the places you expect it to, splitting the conversation on one topic into two places seems like cutting off your nose to spite your face. PMing multiple groups could be done, but it’s a very niche corner case that I expect just wasn’t considered during feature development. “PR welcome”, I suspect.
Actually, if a message is sent to two groups, I wouldn’t expect two copies to be created, but one message to both groups – which Discourse supports
This would be consistent to what happens when you type multiple recipients here:
Yeah, I misspoke on that one – you can have a single PM topic to multiple groups, so if you wanted to support just that, it could work. Multiple categories definitely doesn’t work, though, so you’re then stuck special-casing the “look at multiple addresses” code to PMs, and then handle it differently for categories. Fun times… fun times.