Tools > IMAP profiles

Each IMAP profile accesses the server hosted mailbox for which it is configured.  Configuration is similar to configuring a POP3 host.  You will need to track down the configuration settings for accessing her Live Mail mailbox via IMAP.

Behavior within Pegasus Mail is different in that instead of downloading mail to the new mail folder you will see the IMAP connected mailbox appear at the bottom of the Pegasus Mail folder list.  You can then manipulate messages between that mailbox and "My mailbox" (the local Pegasus Mail mailstore).

Tips:

• You can't drag and drop.  Not at the folder level or at the message level.  You must have already created the folders in My mailbox into which you want to copy messages and  you must use the Copy button.  IIRC, drag and drop of messages appears to work but the messages don't actually get copied.
  
• To disconnect the mailbox, right click on it in the folder list and select "Disconnect this mailbox".

My wife doesn't like Windows Live Mail and wants to change over to Pegasus Mail.  Is there a way to move her stored email messages from Windows Live Mail to Pegasus?

The easiest solution is to access Live Mail using Pegasus Mail via IMAP.  Messages would stay on the server until deleted which can be valuable for accessing from another device.

If she wants to download mail via POP3 and you just need a local copy of the existing messages then you could make an IMAP connection and copy the messages from the IMAP folder(s) to local Pegasus Mail folder(s). 

Thank you, Brian.  It's this option we're interested in:

 If she wants to download mail via POP3 and you just need a local copy of

the existing messages then you could make an IMAP connection and copy

the messages from the IMAP folder(s) to local Pegasus Mail folder(s). 

I'm afraid I don't know what you mean by "make an IMAP connection."  How?  And to what?  Although I've myself used Pegasus for years, I'm drawing a blank on this point.