The flag icons in Mail occasionally disappear, so that each flag in the flags column of any mailbox is just three dots ("..."). This used to happen whenever I had to force-quit Safari, but now a few times a day Safari randomly freezes for just a minute or so and the same thing happens. The flags return when I quit Mail and open it again. Is this just a bug that will be fixed in High Sierra?
MacBook Pro (Retina, Mid 2012), macOS Sierra (10.12.6)
personally I think it is much simpler than you think:
making the "flag" column one or two characters wider will do.
If a Flag is not assigned to an email, then Mail will not show that flag in the side bar. I suggest you create some messages and flag using all 7 colors. (You can rename flags to make them more meaningful).
However, if actual flagged messages go missing this is another issue. This could be a Spotlight issue or Mail might need to be reindexed. Let's start with getting the basics on your Mac. Download EtreCheck. Paste the results here in a reply. This is similar to Apple's System Profiler but has more info that can diagnosis issues on your Mac.
http://www.etresoft.com/etrecheck
More Info on Etrecheck
Safe mode is a joke. It NEVER fixes anything!
Either you have installed anti virus , cleaner , third party apps that is corrupting the mail application .
If that is the case uninstall them .
And if it is an IMAP account , delete the corrupted account and configure it once again , mails are stored on the server they will download in new mail account .
Thanks. I couldn't use safe mode for long because it dramatically slows down my computer and (more important) it kills all sound output.
Diane, the flagged messages do not disappear. The pictures of flags in the flag column get replaced by ellipses ("...").
Uninstall all third party apps on my computer? There are hundreds.
I use a POP account.
You can try deleting this file in your User's Library/Containers folder:
com.apple.mail
Restart your Mac and see if that helps.
If this continues,the Etrecheck report would be helpful.
Flag icons in Mail disappear
