your getting duplicates, two at a time. or you previously downloaded mail and now they are duplicating?

I was getting 2 at a time, one after the other. Now it seems to be OK. Guess when I wrote you, it straightened itself out! Thanks for responding.

I'm having the same problem. I'm getting duplicates of messages that I've previously downloaded, which are still on the server. It just started today; now I have two copies of every message in my inbox.

Duplicates of mail in pop situations have two common causes.

One is duplicates of the same mail. This is almost always caused by an anti virus program and can usually be cured simply by disabling the anti virus program from scanning mail, even if only to allow the current mail to download.

Two the connection to the POP server is lost before the final communication that allows the server and Thunderbird to agreed on what the last message downloaded was. This is also most often caused by anti virus chopping the connection a tad quickly because well we have the mail. Other common causes are a dropped connection to WiFi, someone tripping over the cord or any of a thousand and one accidents.

anyone using pop mail will see duplicates of messages occasionally, and unless you on expensive metered bandwidth, is not really anything more than an inconvenience. At least that is the case if you have the remove duplicates add-on installed to cleanup. https://addons.mozilla.org/en-US/thunderbird/addon/remove-duplicate-messages/?src=ss

see http://chrisramsden.vfast.co.uk/3_How_to_install_Add-ons_in_Thunderbird.html for installation instructions

It worked! Thanks, Matt.