To be clear, this is an email using IMAP protocols.
When I open an email on my phone, and it is marked as "read", then on my Mac it will mark it as "read" as well. But if I open it on my Mac and it shows "read" on the Mac, the iPhone will not make any difference and still show it as "unread". What is the issue?
This doesn't help. I have the same issue. An email read on the iPhone is marked read on my iMac, but not on my iPad. The same when read on the iPad: Marked read on the iMac, but not the iPhone. When I mark a read email as not read on my iMac, the status on the iPhone and iPad don't change. It seems that during the last update of iOS 16.1.(2) something has changed. It sees as if email on the mobile devices don't read the email status anymore.
Hello Lyseir,
It can take some time for things to sync between devices, depending on how they are set up.
To check how often mail is checked, tap on Settings > Mail > Accounts > Fetch New Data. You can set how often the mail will be checked, and therefore updated to reflect what has happened on other devices.
Information on how this works is available here: If you can't receive email on your iPhone, iPad, or iPod touch - Apple Support
Have a good day.
Mail is not showing "read" on phone when already read on other device
