Im working on a email client for MS-Bob and I think pegasus would be a good start. Is the source code opensource or can someone point me to someone who can license it to me? Thanks!

Pegasus isn't open source, but is freeware.
The author has done coding for the line for like 30 years now starting with DOS versions that supported Novell Networks to the current version. It uses some code that he has gotten license to use, so couldn't be made fully open source without a lot of recoding that would mostly be lot of work with little gain.
Is there something that it doesn't do that you want or something you might not know how to get it to do. Not sure what MS-BOB is, all searches seem to show a 1995 Program that was for windows 3.1 an was discontinued in 1996??

Yes MS-Bob is what you are referring to. I am working on patching the built-in email client to support SMTP/POP3/IMAP as it currently only supports the dead MCI service. I was trying to decide between Eudora & Pegasus and though I like Pegasus interface better I guess I will go with Eudora as it is fully opensource. Thanks for responding and helping me out!

Looked at https://en.wikipedia.org/wiki/Eudora_(email_client) and it kind of looks like Eudora is somewhat dead. Transferred over to a museum and mentioned that some code was removed since its rights were not included in transfer?? Looks like last release goes back to 2010??

I looked a Eudora many years ago, but wasn't anywhere as impressed compared to Pegasus.

I actually run Pegasus under Linux using wine since I like it better than anything else I've seen.
Started with Pegasus back in the DOS days with Novell network.

So, might want to look at options.
Good Luck.