I've been running Pegasus 4.73.639 for a number of years, a long time. I didn't realize there was an upgrade available. Now that I'm aware of the upgrade I'm, of course, considering the idea.
My question is the process.

Pegasus is located in C:/PMAIL. Do I simply drop the download, Pegasus 4.81Beta, into that location? What is the correct process? How would I activate the download? I've found instructions for a new install, but nothing specific for the upgrade. What files would I be wise to backup prior to the upgrade?

Before updating, make sure your home and new mailbox locations are the same. I can check this by going to Help > About Pegasus Mail and then clicking the Info button. Do not upgrade yet if they are different. Post back for information about a minor bug that you will need to be addressed.

This is what I do:

• Create the directory C:\Pmail_473
• Copy the entire contents of C:\Pmail to C:\Pmail_473. This is an easy-to-restore backup. Create another backup of C:\Pmail on an external device if you feel the need.
• Run the 4.81 beta installer (w32-481-pb3.exe).
• The installer will default to offering to upgrade C:\Pmail. You want it to do that. If it doesn't point there, cancel out and then post back with details of what it is proposing.

That's it!

Once you are comfortable that 4.81 is working fine you can delete the C:\Pmail_473 directory.

If you encounter any unresolvable problems with 4.81, rename C:\Pmail to C:\Pmail_481 then rename C:\Pmail_473 to C:\Pmail. You will be back to your 4.73 installation.

One other oddity worthy of note in 4.81 is that column width adjustments do not stick between sessions when that window is maximized. This applies to individual folder windows as well as the message list pane in the Preview mode 'Folders' window.