I had this problem - the 'Flagged' folder disappeared from the Mail app and no longer contained any flagged messages, even though I could see that my messages still had flags if I logged into the iCloud website and looked at them there.For me, the solution was to rebuild my Inbox in the Mail app. Select the mailbox you want to rebuild ('Inbox' in this case), go to the Mailbox menu, and select 'Rebuild' at the bottom of the menu. It could take a minute or two, depending on how many messages you have. Suddenly Mail recognized all the flags again, and my Flagged folder re-appeared with my flagged messages in it. The databases associated with your mailboxes are probably corrupted and need to be rebuilt. Simply choosing 'Rebuild' from the 'Mailbox' menu is, but is unlikely to do the trick. If it doesn't, the following steps will fix the problem:.
How to Organize Your Email with Smart Mailboxes in Apple Mail. Matt Klein @howtogeek Updated March 7. We’re going to create a smart mailbox in which messages have been both replied to and flagged. The Difference Between Smart Mailbox and Smart Mailbox Folders. You may have noticed in the first screenshot, there are two new smart.
Quit Mail. from the /Library/Mail/V2/MailData/ folder by opening the folder in Finder ( ⇧+ ⌘+ G) and deleting all files whose names that begin with 'Envelope Index'.
After deleting these files you should 'Secure Empty' the Trash to be sure they're gone.Relaunch Mail and wait. This will take quite some time: many hours if you have a lot of messages.Once Mail is fully launched, search your mailboxes ( ⌥+ ⌘+ F) for 'flagged' messages and wait again.This can also take a surprisingly long time during which it will sometimes appear that nothing is happening, but patience will be rewarded as your flagged messages begin to appear.Depending on how serious and extensive your database corruption is, it's possible that not all of these steps is needed. You might simply try the last step alone and see if it works. However, the missing flags are likely a sign of a problem that will manifest itself in other ways, so the surest approach is to do all the steps above. Rebuild Mailboxes didn't work for me, but it turns out flags are actually part of Spotlight.
I forced a re-index:. drag the drive where your mail folders live (usually your boot drive) to the the Privacy tab in System Preferences → Spotlight. log out, log in.
drag the drive back out of the privacy list and wait while your Mac re-indexes.I found I also had to sort my mailboxes by the flagged column, then click on each flagged item in turn.This solved my issue, and is mentioned in an Apple discussion here.
Tips. To stop the highlighter effect, click the arrow next to the 'Text Highlighter Color' list. Click the 'Stop Highlighting' option. To 'Undo' an unwanted highlighter effect, click the blue 'Undo' arrow above the ribbon.
To add a 'Flag,' click the 'Follow Up' arrow in the 'Tags' group on the 'Message' tab. Select one of the deadline options. The red flag symbol will stand out in your recipient's inbox. You can also add a color category to an Inbox message by clicking the 'Home' tab. Click the 'Categorize' arrow in the 'Tags' group.
Select the preferred color sample.