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too much data transferred alert

  • 3 replies
  • 1 has this problem
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  • Last reply by Ella_hari

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today Thunderbird decided that I have too many emails and got stuck with the alert: too much data transferred. I have been using my laptop with Thunderbird for over 4 years, with all emails safely stored on laptop/in Thunderbird/ and I have never had such problems before. Recently it started compacting my emails (some new function?) and maybe this is the reason. I do not know what happened, I am aware that I have many emails from many years before (which I want to keep), but why it decided to take them again from the server? and what to do know? I tried checking the option in the offline settings to synchronise the most recent messages (beforehand it was: synchronise all) but it is just stuck with this alert. I cannot simply reinstall it because I have 5 different accounts set up in Thunderbird and it is just too much hassle. Is there any other way? Please advise. I got Windows 7.

today Thunderbird decided that I have too many emails and got stuck with the alert: too much data transferred. I have been using my laptop with Thunderbird for over 4 years, with all emails safely stored on laptop/in Thunderbird/ and I have never had such problems before. Recently it started compacting my emails (some new function?) and maybe this is the reason. I do not know what happened, I am aware that I have many emails from many years before (which I want to keep), but why it decided to take them again from the server? and what to do know? I tried checking the option in the offline settings to synchronise the most recent messages (beforehand it was: synchronise all) but it is just stuck with this alert. I cannot simply reinstall it because I have 5 different accounts set up in Thunderbird and it is just too much hassle. Is there any other way? Please advise. I got Windows 7.

All Replies (3)

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re :Recently it started compacting my emails (some new function?)

No it is not new. Compacting is something you should be doing on a regular basis and if you get a lot of emails, then daily would be advised.

It is something you do in order to maintain a healthy Thunderbird. Right click o a folder offer the 'compact' option for that folder. In 'Options' there is also a place where you can set up auto compacting. 'Menu icon' > 'Options' > 'Advanced' > 'Network & Disc Space' tab select checkbox 'compact all folders when it will save over eg: 10MB in total' click on OK


Suggest you read the info at this link as this 'compacting' issue is important. http://kb.mozillazine.org/Thunderbird_:_Tips_:_Compacting_Folders

If you are concerned that compacting all your folders at once is too large a job, then do it manually on a per folder basis. Folders that have had emails deleted from them are the ones that need compacting. EG: Inbox, Drafts, Junk, etc.

If you suspect a folder eg: Inbox may be corrupt then make a new folder and move good emails to that new folder for safe keeping. Then right click on original 'Inbox' folder and select 'compact'. Allow it some time to perform this operation as the entire file will get copied in the profile, the marked as deleted hidden emails will then get removed and the file is recreated, except it will be much smaller.


The 'too much data transferred' alert is a message from the server. Maybe you have exceeded the server limits for how many emails can be downloaded within a given period of time.

Suggest you think about the following ideas.

Possible option 1: In webmail account logged on via a browser. Move all very old emails into suitable folders for storage and do not subscribe to see those folders. So they are only viewable via webmail, after all the odds on you really needing very old emails is remote. At a later date, you could subscribe to see folder if really necessary, but consider this....do you really need to download anything more than a header?


Possible option 2: After the synchronising has finally ended which may take a while due to a lack of compacting and massive files.

In offline mode, Create new folders in 'Local Folders' mail account suitable for storing emails. Copy emails from imap folder into those new folders in 'Local Folders' mail account. These folders do not synchronise with server. These emails are stored on your computer in your profile name folder. When completed create a backup of your 'profile name' folder, so you have a least a copy of everything on eg: external disk drive. Then you can delete those copied emails from the imap folders, thus removing them off the server and releasing space. It will also make the files much smaller assisting with compacting and general improvement in performance.

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Note Before deleting copies off server.... In offline mode...if you can read emails in 'Local Folders' mail account folders then you have got a good copy.

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Thank you for your reply. After a few hours Thunderbird got 'unstuck', the alert is gone and now thanks to checking the option of 90-days-synchro I have only these emails in my inbox on my laptop. The rest is available as a header (unless I open them). I am considering your options and hesitating what to do. I just want to keep these very old emails for future reference (just in case) and not to lose them.