Not a critical issue, but I like to have up to 4 Pegasus inboxes running on my desktop at the same time, so I've pinned the icons on my Windows 10 taskbar. I just updated to 4.80 and notice that 3 of them are now blank and when I go to properties, only one image is now available. I'm guessing this is something new with 4.80.

I also have no idea where to find any non-Pegasus icons to use.

Again, clearly not a critical issue!!!

Your right! The v4.80 Pegasus Mail executable, winpm-32.exe, now only contains one icon. You might find suitable alternatives in the system icons (assuming Windows). These are two of the files that contains numerous icons. Use the "Change icon" button and then navigate to these files to see the available icons.

C:\Windows\System32\shell32.dll

C:\Windows\System32\imageres.dll

I know there are others but these two immediately come to mind.