I still use Mojave on my iMac & MBP [moving from Aperture but not there yet] and have a newer MBP with Monterey on it == but when I read an email on one machine it doesn't sync as read or the mailboxes don't properly sync. Any correction possible or just pay attention and deal with it depending on which machine I'm using?? Obviously I'd prefer that things are in sync esp. Mail items.
iMac 27″ 5K, macOS 10.14
One mail account involved, or all accounts?
Different mail clients maybe using different POP or IMAP paths? (POP will download by default, so not the best for sharing access across clients.)
Older mail seemed a bit dicy at noticing read-unread changes, though Apple seems to have fixed that with recent mail.
Mail itself can accumulate a pile of stale passwords (in Keychain and iCloud Keychain), and I’ve hit cases where those probably-stale passwords may still be used.
Usual suggestion for weird mail issues is deleting and re-adding the account.
The email account must be configured as an IMAP account on the server and all devices that access the email account in order to sync across devices.
To attempt to answer the Q - I'm only using 2 emails, both of which are used in Mail [one is my .Mac account] - both are IMAP -- I only use Mail, not Gmail or any other such -- sounds like I need to delete the Mail app on both machines and start fresh - when time permits. Thanks
I was referring to mail servers in use in my reply, and not mail clients.
Deleting Mail.app won’t resolve this, where that app deletion is even permitted. Mail.app is covered by macOS System Integrity Protection, and such shenanigans are blocked absent disabling SIP entirely. Deleting the mail accounts is permissible.
Actions in Mail that I take on my Mojave iMac & MBP don't sync with my Monterey MBP
