How to stop Mail logs from eating your disk space – Six Colors

The other week, I noticed that the amount of free disk space on my MacBook Air had dropped rather precipitously to under a few gigabytes. As I usually don’t store that many files on that machine—much less large ones—I went poking around to figure out what was eating up all my disk space^.

The culprit, as I reported on Mastodon, turned out to be a Mail log for my iCloud account ^{that had ballooned to an astonishing 28GB—a not insignificant percentage of my 256GB drive. Popping it open, I scrolled through to see, yes, it was just as I expected, a text file logging data from my mail account. I figured something odd must have happened, deleted the file, and thought nothing more of it.}

Fast forward to yesterday, when I went to download the latest macOS Sonoma update on that same machine and discovered that I didn’t have enough space. The straits were not quite as dire as before—I still had 20GB or so available, but not enough for the update to install itself. Despite that, the number seemed low, so I once again went in search of the reason.

And, once again, found that the same Mail log was up to almost 9GB. One time might be a mistake, but two, well, two meant it was time to locate the underlying issue. I popped open the file and took a closer look only to realize that this was logging all of my mail, explaining how the size had gone up so rapidly.

Fortunately, it didn’t take long to uncover the source: an Apple discussion thread led me to the Mail app’s Connection Doctor (Window > Connection Doctor), an otherwise handy tool for troubleshooting mail issues. At the bottom of that window is a little check box “Log Connection Activity.” When that’s active (as I perhaps did at some point a few months back while troubleshooting my iCloud problems)^{, Mail will start keeping extremely detailed logs, which can quickly reach very large file sizes.}

I deactivated the setting and am pleased to report that the logs have been banished, and my disk space is once again my own. But let this be a warning to any who find themselves low on disk space: check those Mail logs, just in case!

[Dan Moren is the East Coast Bureau Chief of Six Colors. You can find him on Mastodon at @dmoren@zeppelin.flights or reach him by email at dan@sixcolors.com. His latest novel, the supernatural detective story All Souls Lost, is out now.]

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