Mail CONSTANTLY re-downloading new messages

[Davmeister]

Hello! Some help if you would be so kind...

My Mac mail client is constantly downloading new messages, see attached.

There is also a discrepancy between the iCloud.com mailbox size, and the Mac mail client size.

It has been like this for months, over high-speed networks, and with enough SSD capacity.

Things I have tried:

A brand new, clean Mac mini bought 2 weeks ago. Signed into iCloud and left everything as default. Its the same.

I have an iMac and and 16" MBP. They do the same.

It is ONLY with iCloud. My NHS Exchange account does not do this.

Side effects: emails come in about 10 mins late. They load very very slowly.

Since this appears to be device-agnostic, I wonder if it is a server side setting.

Scoured the internet without solution. Note: iOS devices are fine.

Whilst I wait for a reply I will try manually adding iCloud to the Mac mail client (i.e. manually input the server details with an app-specific password, and see if that makes any difference).

Any ideas please?

 

[BrianBaughn]

What version of macOS is on the affect Macs?

Have you noticed this after an update to a newer macOS version (on the older Macs) and/or a migration of a user account (to the new Mini)?

The answer to those questions may or may not be relevant.

I'd suggest trying something non-destructive first as a test when you get the time. Turn off all of the affected Macs except for one. On that Mac, create a new, test user account. In that new account sign into the iCloud account and turn on Mail for it.

If, after enough time goes by for Mail syncing, the account in Mail matches up with what's on the web version of iCloud then you probably have some user account issue that wonking up the Macs and the next step would be a careful deleting of Mail data in the affected accounts. There are other, important points to consider before doing this but first find out and let us know if the new user account looks correct regarding the iCloud account.

 

[Davmeister]

What version of macOS is on the affect Macs?

Have you noticed this after an update to a newer macOS version (on the older Macs) and/or a migration of a user account (to the new Mini)?

The answer to those questions may or may not be relevant.

I'd suggest trying something non-destructive first as a test when you get the time. Turn off all of the affected Macs except for one. On that Mac, create a new, test user account. In that new account sign into the iCloud account and turn on Mail for it.

If, after enough time goes by for Mail syncing, the account in Mail matches up with what's on the web version of iCloud then you probably have some user account issue that wonking up the Macs and the next step would be a careful deleting of Mail data in the affected accounts. There are other, important points to consider before doing this but first find out and let us know if the new user account looks correct regarding the iCloud account.

Latest version of Monterey. Has been going on for at least 6 months, so multiple versions.

The new mini was NOT a user migration - it was a brand new account, clean - all I did was sign in on iCloud and let me iCloud files load (no transfer of user data from old machine).

So I don't think creating a new user account will add anything new/solve the issue, as that's essentially what I did last week with the new mini.

FYI manually setting up iCloud mail using manual iCloud IMAP settings results in the same issue.

 

[BrianBaughn]

So I don't think creating a new user account will add anything new/solve the issue, as that's essentially what I did last week with the new mini.

Well that's close to what I suggested. I was thinking that if the troubled Macs aren't connected to iCloud (while doing a new account on one of the Macs) then the possible propagation of some sort of corruption can't occur while the new user account downloads iCloud mail. I forgot to mention the new account probably shouldn't have keychain syncing on.

If it's not something in your user accounts (that has propogated from machine to machine via iCloud) then it must be either an issue with your network setup or with iCloud/Apple itself…the latter being something I don't have the power to fix.

I have a strong feeling that if you contacted Apple about this they'd probably have you wipe every machine and start from scratch…and then see if it's any better. However, there's the possibility that it's something they've seen before and some sort of reset on their end might be the answer.

 

[Davmeister]

Well that's close to what I suggested. I was thinking that if the troubled Macs aren't connected to iCloud (while doing a new account on one of the Macs) then the possible propagation of some sort of corruption can't occur while the new user account downloads iCloud mail. I forgot to mention the new account probably shouldn't have keychain syncing on.

If it's not something in your user accounts (that has propogated from machine to machine via iCloud) then it must be either an issue with your network setup or with iCloud/Apple itself…the latter being something I don't have the power to fix.

I have a strong feeling that if you contacted Apple about this they'd probably have you wipe every machine and start from scratch…and then see if it's any better. However, there's the possibility that it's something they've seen before and some sort of reset on their end might be the answer.

I see what you mean RE: user account. I'll give it a try.