I recently updated to 4.91.1746 I have always had PMail installed on an external drive with the -Roam switch.
I have 675 folders in my Pmail installation.
Lately, when I launch it, it shows me this:
"Preparing Folder Management Layer" and then it takes a long, long time to to load the folders, 25 at a time.
Any clues as what's happening and how to correct it?
Thanks for your help.
Tariya

Please take a look at this thread , maybe it'll help you fixing it as well.

I've had the printer selected as Microsoft PDF and earlier I listed my physical printer. Nothing changed. And what about this notice: Preparing Folder Management Layer? Sometimes I don't have this massive delay loading folders. Maybe something to do with the -Roam switch?
Tariya

How many messages does you new mail folder contain? What about an anti-virus or "anti-malware" application interfering?

I have 5 messages in the new mail folder. It's usually less than that. I only use Microsoft Defender.

I did some searching of this forum and the PM-Win listserv support archives and did not find explanation into what could be causing the problem. A discussion in July 2025 on this forum was specific to this problem, although it was resulting in a crash. The resolution ended up being a clean installation of Pegasus Mail with a restoration of data from the old installation. That is an awfully tedious and potentially technical solution for anyone with multiple Identities in Pegasus Mail and/or not comfortable with manipulating files and folders with a file explorer.

When I see "Folder Management Layer" I think of a corrupted HIERARCH.PM file. A rebuild of it was suggested in the discussion I found but there is not indication that it was tried. NOTE: A rebuild of HIERARCH.PM will result in the loss of the tray structure in the Folder list so is a last resort for any using trays. Planning for rebuilding the tray structure would be important.

The discussion I referred to is here: https://community.pmail.com/index.php?u=/topic/12268/pegasus-will-no-longer-start/post-57853#post-57853

I had two other thoughts while driving today.

1. Could any of the Pegasus Mail folders be large enough to have hit the 2GB file size limit? You could probably easily check this by accessing you mailbox directory with a file explorer and the sorting the list by file size.

2. You mentioned using Microsoft Defender but not whether you have excluded the mailbox directory from active scanning. That exclusion helps to insure that Defender does not interfere with the frequent modification of settings files that Pegasus Mail does. File corruption has been known to occur when an AV product attempts to scan a file that Pegasus Mail is in the process of modifying.

No folders over 1gb.
I'm reluctant to exclude the mailbox directory because I get email from all over the world.
And... I should have referenced this as "locating" not loading folders. I had a similar problem a few years ago and then it stopped. This time it started again when I updated to 4.91. It doesn't happen every time I launch PMail, but often enough to be extremely annoying.

@Tariya, have you dismissed a rebuild of HIERARCH.PM (eg: you use Trays in your folder list)?

I understand this reluctance. I felt the same until I came to understand that malware threats in email are associated with attachment or external sources (links and remote graphics). I don't click links in emails, choosing to copy them and analyze them first, often in Notepad, before pasting them into a browser. I don't allow remote graphics except from known safe senders. As for attachments, I use to save and manually scan them before opening but then came to understand that when you open the directly from Pegasus Mail, they first get written to the system temporary directory where active scanning immediately scans them before they are opened. Of course, extra consideration is needed for any file that can contain scripts. The reason for emphasis on exclusion is that HIERARCH.PM gets updated each time Pegasus Mail is shut down. It is one of the files susceptible to corruption due to interference by anti-malware active scanning. Such corruption is rare might explain the randomness of your slow loading.

Something I can't explain is any relation to the problem and v4.91. AFAIK, nothing changed in 4.91 in regards to folder management.

Redoing the Hierarch... Ouff... I have an elaborate tray setup.
I rarely had this slow "locating folders" when I was in 4.81 and I never saw the Folder Management Layer message until now. Sometimes this slow "locating" goes relatively fast, most of the time it's like a mule pulling a cart. And here's a wrinkle... If I close and open PMail five times, it goes right to my new message folder, no "locating". On the sixth time it's back to slow "locating".

Ouff is right! The elaborate tray setup makes a rebuild of Hierarch a last resort. I hope you are frequently backing up HIERARCH.PM.

Since this issue has come up twice in the past year I think an inquiry to the developer is in order. Before I do that I would like to see details about your installation. This can be generated by going to Help > About Pegasus Mail and clicking the Info button. The resulting display contains installation information that can be copied and pasted into a reply. It does not contain anything personal or of a security concern.

Also, do you use Identities? If so, how many?

Here is the info from Help:

Pegasus Mail for Microsoft Windows
Copyright (C) 1992-2025, David Harris, all rights reserved
Electronic mail to support@pmail.gen.nz.

WinPMail version: Version v4.91.1746, 11 Aug 2025 18:19:07, build ID 1746
Language resources: Standard UK English resources (EN,0,LL)
Extension Manager version: 1.14
Operating mode: Standalone
User name and ID: Admin, 0
Windows version: 6.2
Windows flag word: 0
WINPMAIL.EXE directory: I:\Pegasus\Programs
Home mailbox location: I:\Pegasus\MAIL\Admin
New mailbox location: I:\Pegasus\MAIL\Admin
TMP environment variable: C:\Users\Q3\AppData\Local\Temp
TEMP environment variable: C:\Users\Q3\AppData\Local\Temp
LAN-based SMTP support: N, N, N
NetWare MHS support: N, N, N
Built-in TCP/IP support: Enabled

• WINSOCK version: WinSock 2.0
• WINSOCK path: WSOCK32.DLLCommandline: -RoamActive -Z options: 32768PMR variable: (None)PML variable: (None)MAI variable: (None)NB variable: (None)Autofiltering folders: 0 (0 active, 0 inactive)Last new mail count: 3Message size soft limit: 0 bytesMessage size hard limit: 0 bytesAttachment size soft limit: 0 bytesAttachment size hard limit: 0 bytes

There are 14 identities.

@Tariya, I received a response to my inquiry sent to the developer David Harris. Its content is below.

It could be the USB connection the external drive is connected to - perhaps
its only a standard USB port at 100MB/s?

The "preparing folder management layer" is the point where Pegasus Mail
reads the header section from every folder's .PMM file: performance in this
phase is not affected in any way by the size of the folders - only by the
number of folders, and the speed of the connected device. In essence, the
program is having to open all the .PMM files, read a small chunk of data from
them (about 300 bytes IIRC), then close the file.

I'd suggest checking that the drive has no errors and isn't near death
(problems with bad sectors and so forth), then try plugging it into a different
port. If the problem is persistent and there don't appear to be drive errors,
then getting a faster drive or reducing the number of folders might help.

It's very unlikely to be a problem in the Pegasus Mail code per se - I say this
simply because that code has been around for so long that if there were
obvious problems in it, they would have presented themselves long before
now, and in this case, the problem isn't a case of something not working, but
something not working fast enough.

It's the drive: too slow with the number of folders. Easy fix.
Thanks for all your help. Really appreciate it.
Tariya