I've been so focused on El Capitan not sending mail consistently from Apple Mail that I didn't notice until now that of my 50 or so VIP Mailboxes, only a few of them show anything. Before El Capitan, they all had messages in them and showed a number whenever I had an unread message for that individual.
iMac (21.5-inch Mid 2011), OS X El Capitan (10.11)
Try rebuilding the mailbox.
If that doesn't work, try re-indexing the mailboxes. This can take awhile if you have a lot of mail.
Reindex messages For El Capitan, try looking in V3.
Rebuilding doesn't work because VIP Mailboxes aren't real mailboxes, but rather just an alias or smart mailbox for anything sent by a specific person that is actually stored in another mailbox. Perhaps reindexing might work, I'll give it some thought. Thanks!!
I solved my own problem. Although the individual VIP mailboxes were empty, the top VIP listing with the triangle next to it showed them all. So I went through each person who was shown there, marked one of his/her emails as unread, then suddenly they all showed up in that person's specific VIP mailbox, and it seems to be working now.
Oh well, I decided to rebuild the entire VIP mailbox set, waited two hours, restarted, and I'm back to where I was before!!
Someone on a different site suggested selecting one of the VIP mailboxes, going to View>Sort By>All Mailboxes, then back to the top VIP Mailbox, and everything will be there and also in all the separate boxes. That worked, only then he said that you could change back from All Mailboxes to Inbox Only, and then it didn't work again. I don't fully understand what this Sort By is all about, but for now, I'll just leave it set to All Mailboxes.
Only a few of my 50 VIP Mailboxes show any mail
