If I move a maildir file from Inbox to Archive and then quickly go over to archive and try to open the newly moved message aerc will complain that it can't find the original file in Inbox. This doesn't happen always. Similary, notmuch sometimes looses track of file paths.
I have a similar issue. My setup uses a notmuch account, a gmail account and a microsoft account (the last two using IMAG and Oauth). Most of the time, when I receive an email in any of the accounts the Unified notmuch Inbox folder gets a new email, but aerc complains the file does not exists. I have found two workarounds:
- Close and open aerc again
- Apply any filter, then remove the filter
In both cases the previously received message become accessible as usual.
I see this frequently as well. I'm on notmuch+maildir, and, sometimes, when I receive an email, aerc loses track of it momentarily. The behaviour I see is that I can open it right away when it lands on my inbox but, sometimes, if I open it a bit later, it's lost for aerc (is properly listed but, upon opening it, I get an error). The problem solves itself if I call
notmuch new, which I have a keybinding for, or if aerc's periodic check-mail is run in the meantime.