What mail provider are you using?

I know it is a truly radical idea, but does your provider ignore the pop delete command entirely, or do something else with your email. Google do. Hotmail/outlook do, or certainly used to. I really don;t use them any longer. I think even yahoo do something odd. That is the big three providers internationally. So what provider are you using that you are asking this question about?

hi, thanks, yes outlook. are pop3 accounts useless with outlook then? why does the option on TB to not leave on the server not work? it times out then starts downloading all over again too.

I have known some pop accounts need to compact folders before anything is deleted off the server, so please do this first.

For the Inbox, Drafts and Junk folders:

• Right click on folder and select 'Compact'.

If you have POP and it downloads emails again so you have duplicates then it sounds like the 'popstate.dat' file has a problem. It might be corrupted or you have an Anti-Virus or Cleanup program which has access to your profile and it's messing about with that file.

AS it is unknown whether you have AV and/or Cleanup programs causing an issue: The best method to deal with that is to access the Anti-Virus and set up an exemption for your Thunderbird profile to stop AV from having access to scan etc. Do the same for any clean up software like CCleaner or Wisecleaner.

After setting up the exemption.... To get a clean new popstate.dat file: In Thunderbird

• Help > Troubleshooting Information
• Under 'Application Basics' - half way down is Profile Folder - clickon 'Open Folder' button

A new window opens showing you the contents of your profile name folder.

• Exit Thunderbird now - this is important

• Click on the 'Mail' folder to see list of Pop mail accounts.
• Click on the pop account folder to see contents.
• Delete the 'popstate.dat' file and if you see any others with a number, delete them as well.

Start Thunderbird.

Deleting the popstate.dat file will mean that when you restart Thunderbird you will get a download of anything still on the server, but it should only happen once. The new 'popstate.dat' file should now be up to date and correct.

Please report back on the results after doing all the above.

re : unchecked leave on server - but greyed and checked out is a 'leave for a maximum' which i have as 1 day, there doesnt seem to be an option to uncheck this? I dont want them on the server which is why i chose pop account.

If you have unchecked the 'Leave messages on server', then none of the other settings apply.

If you select 'Leave messages on server' then you can choose how long to leave on server. But you may need to compact folders to force it to work as the folder eg: Inbox still has the email in the folder but the email is marked as deleted and hidden. The compact removes all traces of deleted and moved emails.

As Matt says - google and outlook servers can be a pain.

Gmail - when you delete an email, it can do one of two things. Either it can be put into the gmail Trash (only if you use IMAP) and after 30 days, it will get auto deleted from the 'All Mail' folder and it's gone. If it cannot go into the gmail Trash because you use POP then gmail reads this as only remove the 'label' and therefore email is still stored on server in the 'All Mail' folder. It requires you to periodically log on to sever, access 'All Mail' and manually delete anything that does not have a label applied. Anything you send via gmail server is auto saved by gmail in the server Sent folder - which you will not see if using Pop. It's only visible via webmail.

Please note: if you do not access webmail and delete old mail then it has been known that gmail start to be a pain and only allow a download of a couple of messages until you clear emails off server.

Outlook equally does similar and also anything Sent via outlook server is also stored on server. I think outlook used to have a 'popped off server' folder where it would store those emails for a period of time. Exchange is different again - it's not really designed for Pop. Would not surprise me if this being a pain was designed in order to force users to periodically logon to servers and kill old mail.

Hi thank you so much for the reply and help,

It took a while to sort out, the main problem was it seemed to take forver for the server to catch up, so the emails were still in my inbox for many days even though they had been downloaded. 

I didnt try deleting the popstat file in case i messed up my profile folder by deleting the wrong thing, but until i went on webmail,as you said and manually deleted everything there, it just kept downloading. I think the compacting suggestion helped too, and eventually the server caught up, thank you. It seems to be uptodate now and hopefully easier to keep on top of! Thanks for the help as navigating TB for the first time can feel complex!