Is there a file I can delete to reset that unread message count? I feel like I've done everything that's suggested to no avail.

I have also gone to Mail -> Preferences -> General and verified that Show Dock Unread County is set to 'Inbox' but oddly enough, when I click 'All Mailboxes' the unread count on the Dock changes to 3. I have rebuilt the inbox, I have deleted the email account from the computer, restarted the computer and then readded it, all it did was bring the unread message count from 19 to 16 on my iMac (still - it should be 3). If I create a smart mailbox that shows only unread messages - it shows up with the correct number (3), when I sort by 'Unread Messages' for Inbox, it only shows that I have three unread messages. The MacBook is showing 39 unread messages, and the iMac is showing 16, in actuality there are 3 unread messages. of months or to All so as to sync all email messages. In the Change Account dialog box, drag the slider of Mail to keep offline to the desired no. Now, on the Email tab, double-click on your 'Microsoft Exchange account'. Both Mac systems are using OS X 10.7.3 and I have never experienced this issue before. Go to the 'File' tab and click on 'Account Settings'. My iPhone shows the correct unread message count as well as Outlook Web Access, and on a seperate windows-based computer, Outlook is showing the correct unread message count of 3. I am using a Microsoft Exchange Hosted account (Office 365) and it is the only email account tied to both of my Macs. Just last week I noticed that both my Email Inbox & Mail Dock Icon is showing an incorrect unread message count on both my MacBook & iMac.

Windows 10 mail shows unread mail