Thanks to both of you for responding. I saw your EnableOpsLocks suggestion in another message before I posted, but when I get down to MRXSMB in regedit, I don't see "parameters", so I can't follow the instructions. Maybe that registry entry is different under Vista. I'll research this some more.

 In any case, I have been able to get reasonable performance when I keep the current folders that mail automatically sorts messages to small (e.g. less than 3000 messages). This makes Pegasus usable again.

I share your opinion of Vista, but I'm definitely not upgrading to Windows 7. My home-built computer is old enough that I'll just retire it and build or buy a new one with Windows 7.

Thanks!

I have been using Pegasus for a very long time (and made multiple contributions to the author) and have accumulated many emails. I have set Pegasus to filter certain emails into folders every time I get new mail. This operation has gotten slower and slower with time. Even manually moving emails into folders has gotten excruciatingly slow (e.g. can take 20 minutes for 200 emails). In the past I have tried to manage emails by making archive subdirectory and manually moving old messages into folders in the subdirectory so that the currently-used folders are not too big. I haven't done this recently, and some folders contain 3000 messages.

1. What is the likely cause of the slowdown?

2. How big is "way too big" for a folder?

3.  I am using Pegasus 4.52 on a Vista machine. I don't recall having this

problem before Vista, so could this is a Vista or computer issue? If so what?

4. Assuming this is a mail management issue, what are some good strategies for managing large quantities of mail in Pegasus?

 I have made an effort to search the forum for others with similar issues and haven't quite seen it.

(later) I have tried some tactics.

1. I uninstalled my virus program and disabled everything in startup via msconfig to see if  the problem was caused by interference from another program. No change in behavior.

2. I copied my entire Pegasus setup to an older XP machine. No change of behavior.  So the problem is not Vista-specific.

3. I moved the larger mail folders to an archive directory, and created new folders in the original location, and edited the filter rules to point to the new (empty) folders.  I also deleted empty space and reindexed some folders. Unfortunately I lost my scientific discipline by trying too many tactics at once, so even though behavior is improved, now I'm not sure why.

My guess is Pegasus doesn't do well moving messages to folders with 3000 messages. I would very much to know other people's experience with the size of message folders.

We use Pegasus Mail in a network. All staff mail folders are stored on a server and the program is invoked from the same server.

The only issues I have seen are where staff have folders that either:

Contain in excess of 6000 mail messages: problems usually occur in the index file so that when a mail message is opened it is not the message that was expected.

or

The folder size reaches 2GB: this has resulted in Pegasus Mail crashing spectacularly.

So, I encourage staff to perform regular maintenance - don't allow too many messages to build up in a folder and I monitor folder sizes and alert staff if their mail folders (which as we know is in fact a file), exceed 1.5GB 

FWIW: I have always found that when moving messages between folders, if the destination folder is open the move is much faster.

> I have been using Pegasus for a very long time (and made multiple contributions to the author) and have accumulated many emails. I
> have set Pegasus to filter certain emails into folders every time I get new mail. This operation has gotten slower and slower with time.
> Even manually moving emails into folders has gotten excruciatingly slow (e.g. can take 20 minutes for 200 emails). In the past I have
> tried to manage emails by making archive subdirectory and manually moving old messages into folders in the subdirectory so that the
> currently-used folders are not too big. I haven't done this recently, and some folders contain 3000 messages.

This is not all that large, I move mail around in folders much larger without problems.  With IMAP4 though moving anything is painful since this is a very busy protocol.

> 1. What is the likely cause of the slowdown?

A guess, it might be opportunistic locking adding a 1 second pause on each item.  Doesn't sound like much but it can turn into forever when you are doing 1000 moves.

Here's something you might try using RegEdit.  It's actually very easy to do and for me it fixed the one second pause when working with the mail store on a Win2K type server.  You need to create a new DWORD OplocksDisabled and then set it to one. You can do this on the Windows server as well to turn off OPLOCKS for all.   

Configuring opportunistic locking in Windows
http://support.microsoft.com/default.aspx?scid=kb;EN-US;296264

1.     Use REGEDIT and find the following registry entry.  HKEY_LOCAL_MACHINE | System | CurrentControlSet | Services | MRXSmb | Parameters

2.    Select Edit | New | DWORD value

3.    Enter OplocksDisabled for the value name and 1 (Disabled) for the value data.  The default is zero (not disabled)

4.    Exit REGEDIT and reboot your system.  

You can also deny the granting of opportunistic locks on the server by setting the DWORD "EnableOplocks" registry entry to value of zero (Disabled) in

HKEY_LOCAL_MACHINE | SYSTEM | CurrentControlSet | Services | LanmanServer | Parameters

Note  The EnableOplocks value configures Windows-based servers (including Workstations sharing files) to allow or deny opportunistic locks on local files. The default for EnableOplocks is 1 (Enabled).

> 2.  How big is "way too big" for a folder?

IIRC it's around 16000 messages when the sorting gets really slow.

> 3.  I am using Pegasus 4.52 on a Vista machine. I don't recall having  this problem before Vista, so could this is a Vista or computer
>     issue? If so what?

Could be, never can tell with Vista.  It's generally a piece of trash.  Win7 it really a bug fix for this OS and it's quite an improvement.

>
> 4.  Assuming this is a mail management issue, what are some good strategies for managing large quantities of mail in Pegasus? I have
>     made an effort to search the forum for others with similar issues and haven't quite seen it.

Archive it off to a different drive/directory using the @add mailbox to list@ function.