This started happening on 21st April, but only on certain folders. Whenever I click on the email I want to look at, the header in the email list goes completely blank. The email is there and can be read, and if I click on a different email the header details will show again. It only happened on new emails which arrived on or after that date. If I delete the summary file and allow it to rebuild the problem goes away for all existing emails, but is still there for any new emails which arrive. I'm sure it is something really simple, but I have run out of ideas. Can anyone help? Thanks, Paul