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Jim Dysart Author

Level 1

13 points

What is MailQuickLookExtension.appex

What is MailQuickLookExtension.appex is causing huge drain on CPU in Activity Monitor and computer MBP 15" 2016 Catalina is getting hot.

What is the issue?

Posted on Feb 7, 2021 4:41 PM

Top-ranking reply

steve626

Level 6

11,309 points

Posted on Feb 7, 2021 6:12 PM

My recollection is that this extension is used when you utilize Quick Look to get an advance glance at attachments in Apple Mail.

Do you have Quick Look open on an email message?

Try closing all windows in Mail. Leave Mail open. Is the CPU drain gone? If not, then quit Mail. Recheck -- is the cpu still running hot? Restart the computer. Before reopening Mail, see if the cpu activity drain issue has gone away. Then reopen Mail and check again.

If it is still problematic while you have no windows open in Mail, then restart your Mac and hold down the shift key, it will start in Safe Mode this way. But will take maybe 20 minutes to start up. Then restart normally.

Hopefully this will cure it.

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What is MailQuickLookExtension.appex

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