So I’m wondering if this is intended behavior or just a bug in Mail.app. I’ve noticed emails I know I have sent to be missing in the Sent folder. Turns out those emails do show up, but only in my Archive. It appears whenever I send an email for which I am also a recipient (eg. sending an email to a bunch of people as BCC: with only myself in To:) Mail will at first show it in Sent, then once it arrives back on my Mac it will also show up in Inbox, and finally, when I move it from Inbox to one of my archive folders that’s the only location I’ll be able to find it. The copy in Sent is gone. This is using IMAP.
Two things I’ve observed while trying to figure this out is that the copy in Sent will not disappear if I move the email from my Inbox into Archive instead of a specific IMAP folder. The Sent copy also seems to stick around if there’s only one recipient in BCC and myself in To. If I put several people in CC with myself in To I will observe the missing copy in Sent.
Is this really intended behavior or is it a bug? Is it caused by a specific setting I have inadvertently chosen? Or is this some kind of server-side shenanigans? It’s IMAP, but work so unfortunately not my own mail server. Come to think of it, since it’s work it’s also gmail so not even real IMAP, but rather whatever Google has morphed IMAP into.