After I upgraded to macOS Catalina—or perhaps after I replaced my laptop because of the spilled drink catastrophe—I’ve been having problems with mu/mu4e. That’s serious for me because they are my primary email client. There are two problems.
First, mds and its helper apps were running not quite continually but regularly. Mds is the indexer for Spotlight, the macOS utility that provides system wide content searches. Mds uses a significant amount of CPU time when it’s running. So much so that the laptop gets significantly hotter. My hypothesis is that mds was getting kicked off every time mu ran mbsync to sync with the IMAP server—every 5 minutes on my machine. After it finishes running, there was a fairly short period until it got kicked off again.
I fixed that problem by telling Spotlight not to bother indexing my mail repository or the Xapian index that mu maintains. I can’t find anyone else complaining about this, which is odd because both my Spotlight configuration was the default (before I told it not to index the mail) and I’m not doing anything special in my mu4e configuration.
The second problem is sometimes it can take 30 seconds or longer for the email list to come up. Less often there is also a delay when I select a message before it appears. The delays appear to happen when mu is running. I haven’t figured out what’s causing this yet. I’d be happy to hear from anyone with some wisdom on the matter.
I’m inclined to think these problems were caused by the OS update and hope that they’ll be resolved when Big Sur is released. That happened before with a delay when invoking the browser from an Org link: the problem resolved itself with a new OS release. Again, if anyone has seen similar problems, let me know.