Pegasus Mail is probably doing this.  This only occurs for emails that are COPYSELF emails.  Pegasus Mail adds a special X-CS header to such emails to flag them specially as COPYSELF emails.  When Pegasus Mail sees this header in such a message, it knows to display the To: field instead of the From: field within the folder window.

I'm not exactly sure from your email whether you're checking this from Pegasus Mail or from Outlook.  Pegasus Mail doesn't have a To: field column in the folder window.  This is the reason for the X-CS field in the first place, so that you can see the recipient names rather than your own name.

I've finally managed to get all my emails across to Exchange, though not with the primitive methods that Pegasus is only capable of.  I started that, but got fed up after a couple of hours, and bought a piece of software that did the trick quite well (Transend Migrator).

However, I notice now that everytime I SEND an email and save the sent email in one of the IMAP folders, the header in the TO: column in the message list window for that folder ALWAYS shows MY name, not that of the person I sent it to. If I open the message, it's all correct - just not in the message list window.  And it only happens is some folders but not others. And it seems to do it to all emails in the folder, not just the new ones.
 
All my folders are subfolders of the inbox so as not to get the mail folders cluttered by the plethora of  all the other Exchange/Outlook folders.

I don't know if there is a causal relationship between this phenomenon and whether I transferred that particular mailbox by hand or using the Transend app.  But I do know that every new email that I send now ends up behaving that way.

 Is this my problem, Pegasus, or Exchange?

Shah