I recently noticed a 'change' in my mailbox listing but couldn't really see what had changed - the list just looked different!

Today I realized that one of my [Filing Tray]s was missing.

I contained about 10 Message folders and I can (with a [Search]) see that they still exist and I can look at them.

I don't know what the extention is for a Filing tray and even if I did I have no way of knowing how to restore it.

Can anyone suggest a solution (to restore the tray)?

I'm still using V4.7 and am cautious about upgrading 'til this other issue is resolved.

TIA.

PANIC Over !!

Yet another reason to thouroughly recommend Pegasus as THE e-mail Client !!!

Knowing that the individual message folders were at least accesible I looked down my list and sure enough every one was listed. It therefore meant that all I needed to do was create a new [Filling Tray] and move the folders into that. - BRILLIANT.

I have long promoted Pegasus on the basis that moving it from one PC to another was/is a very simple matter of copying the data into folders with the same name and everything just 'WORKS'

How the [Filling Tray]s (there were about 6 affected) got lost I can't be sure but I did get a warning at the weekend about space on the hard disk being small, and I've since cleared that so that could well be the reason.

Filing trays are not physical so there is no file associated with each tray. Instead, they are virtual, meaning that the tray structure is in the HIERARCH.PM file which contains what you see when you open the folder list. The HIERARCH.PM file gets updated at shutdown and checked at startup. Should the HIERARCH.PM file get corrupted, which is a possibility in a low disk space scenario, a new one will be created during the next Pegasus Mail startup. When that happens, the tray structure is lost. This is rare, but not unheard of. A trick I use to help rebuild a tray structure is to reference the tray name in each of its folder names. At the office I had trays for customers and vendors, with many folders in each tray. Customer folder names were prefixed with "Cus" and vendor folder names with "Ven".

As for using v4.7, I recommend upgrading to the v4.81 public beta provided your Home and New mailboxes are located in the same directory. You can find their location in Help > About Pegasus Mail > Info button. If they are different, there is a workaround to a POP3 and SMTP host file recognition issue that you'll need to know about. As for v4.80, there were some bugs in it that make it worth skipping.

I'm glad you found your way on your own. Kudos. What you just did is exactly what I was about to recommend.
The Folders pane structure is stored in hierarch.pm file i.e. filing trays disposition and its folders. The other control file is folstate.pm that holds the information about trays that were open at the last shutdown. These and other control files can become corrupted for a number of reasons. Therefore, it is advisable to keep backup copies of these files as a way to restore them to their last known good condition.
Finally, these control files are automatically created by Pegasus if missing. If hierarch.pm is missing, you will have the Folders pane but not in a structured way (no filing trays). If folstate.pm is missing, all filing trays will be shown closed.

Thanks to you both for those explanations. I've been using (and recommending) Pegasus for over 30 years and never had need for such information.

I do have a backup system so I might have been able to recover the folstate.pm & hierarch.pm files if I'd noticed the problem when it occured but the backup happens at 7pm every day so even a triple archive would now be over-written.

I'm somewhat averse to [Beta] versions so while V4.7 is operable I think I'll retain it I'm still running Win 7 Ultimate on my main PC, (just noticed that is also your O/S Euler!!) though I do have Win 10/11 PCs as well - and even an XP unit running my CNC machine.