email between iPhone and iMac do not sync

If you are using the Mac Mail client on both devices (and iCloud mail using IMAP), created the connections using the standard settings when setting up iCloud they should be in sync. You might want to open the mailbox app on your Mac and choose Mailbox from the Menu bar and select 'Synchronise all accounts' and see if that brings them back in sync.

If you tried the re-sync option then I would suggest that on your Mac, assuming you are using the Mac Mail client, choose MailBox, Rebuild from the menu bar. This may help. If this fails, and again assuming all your devices are using IMAP to handle mail which means your mailboxes are left intact and contain all your mail on the server, try the following:

1. Log into each of your mail accounts using a web browser and check that all your mail and folders etc., are present and correct.
2. On your two computers (you don't say if they are Mac) take a Time Machine backup and for the iPhone take an iCloud backup
3. On each device I would then suggest 'signing out' of your mail accounts and choose to remove local content
4. When all devices are signed out of mail - reboot/restart each device to clear any stored cache
5. On each device in sequence re-add your mail accounts and give each device (particularly the first one) time to sync with the server and download mail content.
6. Repeat and see if the devices now re-sync.

Please advise if this process works for you.

Hi - do you have any other suggestions? I have two computers and an iPhone, all up to date with the most recent updates, and my mail will not sync across the devices. I have tried to synchronize all accounts, but this doesn't work either.

Thank you for your response. I did all of these things and actually ended up talking to Apple on several different days, giving them screen recordings, details about my devices, etc. It was escalated to Apple iCloud engineering and as of yesterday afternoon, my account was fixed. :-) So there was actually nothing that I did on my end to make it work.

I have a followup call with Apple tomorrow and maybe (?) I'll find out what the problem was. Either way, it's working normally now, and it seems like it might have been unique to my account.

I am having the same issue! All my devices (apple products) are up to date and yet they have stopped syncing the mail. The calendar is working fine though. So frustrating! I don't want to log out of everything and then restart again! what can I do?

That's good to hear - would be interesting to learn what action they took. From managing other mail systems, I would anticipate them having re-set the sync state on each of your devices looking to the mail server. Only an assumption, but the last option I suggested was to try and initiate that reset from your side - clearly needed an active action from Apple.

I recommend scheduling a call with Apple. There’s nothing you can do on your end, from what I understand. Hopefully they are working on a global fix?

I still don’t know what the issue was. Just that they fixed it. 🙂