Thanks caisson for response.  I reinstalled Pegasus and it started working immediately.

Perhaps that is the first thing to do when there is a problem, though I do not know how the Pegasus program files (and it has happened with other programs too) should become damaged.  No doubt theories in answer to that are manifold, so I'm just happy that all is now well.

I have to switch to IMAP courtesy of UK2.  I followed the set up procedure for IMAP without SSL through the Tools/IMAP menu carefully using the settings provided byUK2: 

Server/Hostname/Address: chimail.uk2.net

Username and password as confirmed by them

UK2 suggest using outgoing ports  587, 8025  Is this important ?  If so how do I set it.

Incoming port 143

Timeout and Mailbox reference left blank and all other settings left at default.

RESULT:  There isn't even an IMAP folder created in my folder manager window (does this appear at set up or after the first successful login ?) so is my IMAP profile within PMAIL incorrect  ?

I have PMAIL 4.72.572

What happens when you select that profile and click on connect?

(The outgoing port information is not pertinent to your IMAP setup and should only be used if it is different to your current outgoing configuration in Tools | Internet options.)