Symptom

My IMAP account in Apple Mail shows messages that I previously marked as read as unread.

Resolution

Apple mail uses a database to store details about the emails in your account. Sometimes Apple Mail fails to correctly set the ‘read’ flag on mail in your IMAP account and causes the database to go out of sync.

To resolve this you may need to rebuild your mailbox in Apple mail to update the list of messages it contains.

  1. Select your Ecenica mailbox in the Mail sidebar
  2. Click Mailbox > Rebuild from the menu.

When you rebuild your mailbox the emails and attachments stored on your Mac are deleted and then downloaded again from your Ecenica mail server. During this time your mailbox will appear empty until the download is complete.