I have three other email addresses where this is not a problem. Also, I can log into Comcast.net and delete all the inbox messages after one get new mail on Pegasus, but that does not seem to help. Lythande's answer below may be the solution, and I am going to go try it, if I can find the appropriate spot.

I have one Comcast.net userid with a runaway inbox on Pegasus. Every time I get the mail, it brings in dozens of copies of the same email, so my inbox has thousands of emails in it. I have three other Comcast.net userids, and they do not misbehave in this manner on Pegasus. I am reluctant to switch to a different email package, because I have many emails that I want to be able to find, I desperately need help in controlling this runaway inbox. This problem is with a Windows XP Pro operating system.

> I have one Comcast.net userid with a runaway inbox on Pegasus. Every time I get the mail, it brings in dozens of copies of the same
> email, so my inbox has thousands of emails in it. I have three other Comcast.net userids, and they do not misbehave in this manner on
> Pegasus. I am reluctant to switch to a different email package, because I have many emails that I want to be able to find, I
> desperately need help in controlling this runaway inbox.  

Try using File | Selective mail download to remove the duplicate messages on the server to begin with.  Next talk to the people at Comcast and ask them why you are getting the duplicates in you inbox.

Also, check the problem id under tools/internet options/Receiving (POP3) click the troublesome id and click edit.  Make sure there is a check in the box for "Delete mail on server once it has been successfully retrieved".