Could you provide a copy of a message with a TIFF attachment where this happens?  If you can mail it as a zipped attachment to techsupp@tstephenson.com.

Edit:  FWIW, the attachment viewer automatically displays a TIFF type file when I select to view it.

I am having trouble with attachments sent to me. TIFF files crash Pegasus when I try to open it, and when I click on Word files nothing happens. I can't save or open them. I've been using Pegasus Mail since around 1995 and rarely get stymied, but this is a major inconvenience.

If you are using a recent version, check what you have in Tools / Options /Content viewers for those types of files.

If you can open them by clicking on them when not using PegasusMail, then it's simpler to set up the viewer entry as 'Let Windows choose..'

I am using Pegasus 4.41 for Windows. I did add the tif extension and selected "Let Windows Decide," but same results: it crashed PM.

--mark