This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

How to stop downloading duplicate copies of large e-mails (containing many photos). No problem with other e-mails.

  • 5 replies
  • 1 has this problem
  • 1 view
  • Last reply by Zenos

more options

On very large e-mails with many photos attached Thunderbird continuously downloads copies of the specific e-mail. When I move the offending e-mail out of the server in-box Thunderbird behaves normally. E-mails are downloaded normally until one of the large e-mails is encountered and then it continuously downloads copies of that e-mail until I do the move on the server. Seems like Thunderbird is failing to mark the large e-mail as having been downloaded.

On very large e-mails with many photos attached Thunderbird continuously downloads copies of the specific e-mail. When I move the offending e-mail out of the server in-box Thunderbird behaves normally. E-mails are downloaded normally until one of the large e-mails is encountered and then it continuously downloads copies of that e-mail until I do the move on the server. Seems like Thunderbird is failing to mark the large e-mail as having been downloaded.

All Replies (5)

more options

What anti virus do you have scanning your mail and causing this issue I wonder to myself.

Norton's probably. It has the worst reputation for this.

more options

My anti-virus is Avast. What does anti-virus have to do with it anyway? Regular e-mails download properly as do e-mails with a spreadsheet as an attachment. I think it is Thunderbird failing to mark the e-mail on the server as previously downloaded.

more options

Richbee said

My anti-virus is Avast. What does anti-virus have to do with it anyway?

Only everything. And Avast is a known troublemaker. Not this specific issue, but pretty impressive none the less https://wiki.mozilla.org/Thunderbird:Testing:Antivirus_Related_Performance_Issues#AVAST

What is almost certainly happening is Thunderbird request the next mail, a large one, Avasts starts dicking around scanning it and by the time is has done playing in the sandpit the server has dropped the connection. So Thunderbird tries again, asks for the mail is never properly received and again Avast gets into the game and the same issue repeats until someone get in an manually stops the foolishness.

If you have any Add-ons, SPAM tools or anything else Avast has installed in Thunderbird disable them immediately. Disable email scanning and you will be exactly no worse off than people who use web mail as far as security goes, but you almost certainly will not have this issue.

Simply put, getting email with an anti virus is like getting reticulated water through a water meter, When the water stops flowing no one looks to the water meter, or the flow regulator but they are critical to the continuity of supply.

more options

As far as I know Avast has not installed any add-ons in Thunderbird. I did disable the individual e-mail scanning option (referred to in the link), but I still had 36 copies of an e-mail that had only 4 attachments (a 1 page letter, a 4 page letter (Word) and 2 pdf files of the Word documents).

more options

Well, to check out Matt's suggestions, start Windows in safe mode and start Thunderbird in safe mode and see if these downloads then succeed.

Repeated download attempts are usually indicative of an incomplete download. This can be due to AV operation, or a malformed message on the server.

Having acquired one usable copy, a pragmatic approach would be to visit the account's webmail site and delete it there.