Yesterday a friend asked if I could call her elderly mother who lives several hours away because her mom's iMac was really slow. A 2017 i5 8GB w/ 1TB HDD running MacOS Mojave. "All mom ever does is email". So I called mom, had her reboot, try Safe Mode, no change. Talked her through signing into iCloud and starting the Messages.app for the first time. About 2+ hours on the phone I was screen-sharing and seeing what was really going on. Despite having a 1TB HDD she only had 1.3GB free! Her Console and Activity Monitor showed normal except for a tremendously-high CPU Time for her Mail.app. No weird Safari Extensions, Grand Perspective showed nothing odd, system log files all a-okay; it was a pristine install of MacOS. "All I ever do is email." I know a lot about Macs but I was stumped. This was a mystery.
Any guesses?
Finally -- out of desperation -- I sent her an email from my own Mac and watched it received and displayed thru screen sharing. Then I noticed an odd line of text in her Mail window: "Apple Mail Connection Logging Enabled". WTF? Never seen this before. Sure enough this was the culprit. Buried in Mail's Connection Doctor menu is the ability to permanently log ALL Mail activity. I've been using Macs for 20+ years and I own around 30 of them and I've never, ever seen this. So how long has it been logging? Forever. I'm guessing it was mischievously turned on at the retail store before she bought it and it held the setting across MacOS updates. So it's been diligently logging EVERY SINGLE MAIL FETCH ATTEMPT for about 5 years! How big was the log file? Well the IMAP log was a 691.43GB TEXT FILE and its SMTP companion was ~250GB. It took over an hour for MacOS to delete these two files. I unchecked the Logging box, rebooted, and the computer is happy & responsive once again.
Is this the World Record for the Largest Text File???
Any guesses?
Finally -- out of desperation -- I sent her an email from my own Mac and watched it received and displayed thru screen sharing. Then I noticed an odd line of text in her Mail window: "Apple Mail Connection Logging Enabled". WTF? Never seen this before. Sure enough this was the culprit. Buried in Mail's Connection Doctor menu is the ability to permanently log ALL Mail activity. I've been using Macs for 20+ years and I own around 30 of them and I've never, ever seen this. So how long has it been logging? Forever. I'm guessing it was mischievously turned on at the retail store before she bought it and it held the setting across MacOS updates. So it's been diligently logging EVERY SINGLE MAIL FETCH ATTEMPT for about 5 years! How big was the log file? Well the IMAP log was a 691.43GB TEXT FILE and its SMTP companion was ~250GB. It took over an hour for MacOS to delete these two files. I unchecked the Logging box, rebooted, and the computer is happy & responsive once again.
Is this the World Record for the Largest Text File???
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