OK, I'm glad it's solved.

I have been using Pegasus for several years with a Cox Cable Pop3 server without issue. However lately some messages I receive in my cox mailbox fail to download into Pegasus, but are deleted from the server.  (I do have the option checked to delete messages once downloaded). I have not done any recent updates to either windows XP, Pegasus, or cox for some time. Does nayone have any ideas what I can do to correct this?

I did a little additional test on this issue by setting up a Thunderbird account to my Cox cable, and a message downloads fine to Thunderbird, but does NOT download to Pegasus. I currently am not deleting messages on my server from Pegasus, but something is NOT right. I believe that this test confirms the issue is in Pegasus and not on the Cox cable side. Help please.

Could you provide some more information - What version are you using?  What download controls do you have set - have you asked for only unread mail for instance?  Do you download from more than one computer, such as using webmail to access this mailbox?

I am using Pegasus version 4.41 (which was working until a few days ago). I had changed no settings before this problem began. The only setting I have changed since is I unchecked the option to "delete mail on server once it has been successfully retrieved" so that I can retrieve important emails in Thunderbird.

The only option I have marked in download controls is "leave on server" for default action after filtering. I do NOT have "Download only unread mail checked".

Also, I am using  Spamkiller 2.83 to filter spams (I do not use the filters in Pegasus). Spamkiller filters the messages in the cox account and if NOT SPAM, leaves them in the Cox server inbox. I have operated this way several years without an issue. This problem only started a few days ago and no I have not recently installed any new software or updates just before the problem started. I do NOT allow Microsoft to run updates automatically, only to notify me of updates and I have not recently had any of them.

I can use Cox webmail to read my email, but not normally do so. And no I have not used webmail or another computer to retrieve email from this cox account for quite awhile.

Since the Cox mailbox is my primary email account, I must resolve this.

Finally, to add a little more confusion, by wife's PC is configured the same way with Pegasus Mail and she can download email from her Cox mailbox without a problem.

Do you have different identities? Another identity may be accessing the same mailbox.

If you check the box marked "Create internet session logs" on Tools / Internet options, you will create text logs called TCPnnnn.WPM in your home directory.  By examining these you can see which messages are being offered to Pegasus Mail and what the response is.  If no messages are being deleted by PMail, then something else is removing them.

I don't know anything about Spamkiller, but does it keep a record of the actions it takes?

Well, call me a stupid idiot with CRS (Politically correct version, "can't remember stuff"). I must have been playing around with SPAMHALTER and turned it on. All of my missing emails were in the SPAM folder I had pointed SPAMHALTER to. I have now turned off SPAMHALTER and will need to get some emails to check it, but feel confident this is the solution. Thank you very much for your time.