Yosemite Mail not showing correct unread counts

same issue with my iCloud account (.mac address). i found that if toggle the "organize by conversation" option (from the window menu) it corrects, but only until the next email comes in - much like rebuilding the mailbox.

Hello, Having the same issues here with Yosemite and a Gmail account.

The inbox message count is sporadic with its unread count. It seems to function correctly when starting mail, hovever email that arrives later will not increment the unread count. The other gmail account works fine and has far less email in than the problematic one, I'm wondering if its struggling with size somehow.

And as if my magic, everything seems back to normal!

The only thing done apart from deleting and rebuilding the mailbox was to repair Disk Permissions.

There is an issue however with sent email with attachments not appearing in the sent folder which another user seems to have also.

Partial solution for Yosemite mail smtp not syncing with blueyonder-gmail with attachments

Are you talking about in the sidebar (left side) or in the title bar (top of the window)?

If the latter, this seems to occur if you switch to view a smart folder, and then switch back. In some cases, the number will go away. Quitting and restarting Mail will fix it. The only way I think you can stop it happening at this point is to not use smart folders.

try rebuilding your spotlight.

To do that, go to spotlight preferences, then to privacy tab. then add your whole macbook hdd to the privacy section to de-index it. close pref's, then go back and remove that item to start re-indexing. once it's finished, your unread counts should now be correct.