Mac Mail CPU 120% when idol

[Peter Franks]

Any reason why Mail is showing 100% and now 120% CPU and won't send an 18KB email. Fan just going mental.

It's been shut down and re opened etc., but just doing the same. There are no big emails with any attachments coming in or going out. Mail on phone working fine. It's just on the MBP running Sierra. Any quick fixes. Update to High Sierra? Was this a known fault for anyone running Sierra?

 

[BrianBaughn]

I've had issues with Mail, not necessarily with Sierra, that it seemed could only be cured by turning off Mail for all accounts (or even removing the accounts), deleting the contents of the Mail folder at ~/Library/Mail, and re-enabling or re-adding the accounts.

 

[Peter Franks]

Thanks Brian, is that a big job, and did you lose the 'offline' emails that are saved? It's only one account, but it's a business one with a lot of old saved mails offline/(On My Mac).

I've had it a few times on the MBP with Sierra. I didn't even know it could go over 100% on CPU, I thought that was the limit. It's usually only Safari/Chrome that give the fans the biggest run on here so surprised. It just completely freezes on the smallest of emails.

 

[BrianBaughn]

Thanks Brian, is that a big job, and did you lose the 'offline' emails that are saved? It's only one account, but it's a business one with a lot of old saved mails offline/(On My Mac).

I've had it a few times on the MBP with Sierra. I didn't even know it could go over 100% on CPU, I thought that was the limit. It's usually only Safari/Chrome that give the fans the biggest run on here so surprised. It just completely freezes on the smallest of emails.

I should have mentioned that! Yes, deleting that folder's contents would delete "On my Mac" emails and folders. Makes the process trickier...another reason not to have email stored that way...the main reason being folders accessible on every device.

You'd have to export the "On my Mac" folders and re-import them.

 

[Peter Franks]

Great. Thanks for your help.

 

[Fishrrman]

I generally leave the Mail app "closed" (not running).
I open it, check my mail, and then quit it.
No problems with it using up CPU that way!

 

[Peter Franks]

It's doing it ten fold today, getting on my nerves, Force Quit doesn't do it, only restarting the MBP stops it, and then after a while.. fan and CPU 120% and counting. I'm not sure what causes this because even when nothing coming in it starts up.

I don't suppose the thousands of back up emails in 'On My Mac', is relevant, as they are now growing into quite a sizeable number?

Why do you quit it though, because it's a known fault?