Thanks for the input, Brian

We are expecting delivery of a new Windows Server 2012R2 data server early next month as our existing one is near capacity, so I will see if it affects the way Pegasus behaves. Pegasus Mail's mail folders are all excluded from AV scanning, and we use Sophos  -  Windows Defender is not installed. NIC drivers are broadcom, downloaded from Dell's support site.

Hello

We use a networked installation of Pegasus Mail and Mercury. They are installed on a Windows 2008 64bit storage server which is a member server in our Windows Active Directory domain. All clients use a Windows Desktop shortcut to access the Pegasus Mail excecutable, which uses a DFS path. We've been using it this way for the last 7 years - prior to that we used UNC paths.

Since upgrading to 4.72 (4.72.572, Feb 19 2016, build ID 572), we have found that temporary freezes, which occasionally occurred with previous versions, are happening more frequently. The weird thing is there does not seem to be any common causes. We have 30 clients on the network. The majority use DHCP and some have static IP addressing. Some negotiate two switches when accessing our servers, and some three of four. Some clients that need to negotiate three switches do not experience any problems, others, like my PC a Dell Precision T3610 experience freezes 4 or more times a day. This happens when compiling a message (presumably during autosave), sending, moving, opening - the only common theme I can think of is network access. However, if there was a problem with our network I would expect more PC's to have the same problem, especially as three quarters of the clients use the same hardware and software.

I have run dcdiag tests against the domain and have also used the /test:DNS option which it passes with flying colours. Ping results against the domain controllers (2), and against the member server that hosts Pegasus Mail and Mercury are instant.

I have seen this mentioned elsewhere in the forum, and from what I can remember there was no resolution at that time. I don't expect a resolution now, but wondered if anyone else using the same/similar deployment had noticed similar behaviour or would like to offer any insights/thoughts etc to the discussion.

Our setup is similar to yours.  Pegasus Mail and mailboxes on a Windows 2012 server, 14 users, Mercury feeding the mailboxes and doing the sending.

We experienced noticeable delays across all apps that ran from or accessed data on a server when using DFS name spaces.  We had to abandon it.  At the time we had one Windows 2008 server and one Windows 2012 server.  We have since upgraded the 2008 server to 2012 and are testing DFS once again.  Early tests have not shown any of the problems experienced when the 2008 server was in the picture. 

I also made the change from UNC paths to mapped drives solely out of aggravation at having to reconfigure all of the shortcuts on every PC whenever a server change was made.  Drive mapping via the login script has been reliable.

A given is that the mailbox directories are excluded from active AV scanning.  Is Windows Defender in the picture?  I became very suspect of it as the cause of network access delays during setup/configuration of a Win10 workstation.  I can't say for certain it was the cause but the problem was resolved after getting our enterprise AV product installed and replacing the default WIN10 NIC driver with one downloaded from Realtek.