After upgrading to Confluence 2.7.1, emails sent to users who use Microsoft Entourage 2008 (Macintosh) as their email client sometimes (maybe always) show up blank. A look at the actual message (using Message->Source in Entourage menu) reveals that the message contains all of the right data. The same message on the IMAP server downloaded to alternate email clients (including MS Outlook on a PC, iPhone Mail, and Apple Mail) renders correctly.

There is however another user who has reported the same problem with MS Outlook, though this is not consistent with other users. At least two users using Microsoft Entourage at our site are receiving the 'blank' emails. Saving the message in its original format using Entourage again reveals that the contents of the message are there in the message.

A hunch that this problem was an HTML display problem led me to edit the message and remove all of the stylesheet information (removing the <style>...</style> elements from the HTML inside the message. Sure enough, that edited email message displayed correctly in Entourage. Also, switching to 'Text' format for notification emails allows the emails to be viewed, providing further evidence the problem is an HTML display issue only.

So it seems that the problem is with Microsoft Entourage (latest update to MS Office/Entourage 12.0.1 didn't fix the issue). However, the fact that it seems to occur on at least one instance of MS Outlook leads me to believe that perhaps something in the underlying stylesheet could be adjusted to work with Entourage and Outlook reliably. If the stylesheet could be updated so that it renders properly in Entourage (probably some minor bug in Entourage/MS Office HTML rendering), this would be most desirable.