Compacting is something you should be doing on a regular basis. As an example: I delete quite a few emails each day, so will compact the 'Inbox' and 'Junk' daily. If I compose a lot of emails on that day, I will also compact the 'Drafts' folder.

When you delete an email, it is not fully deleted. It is hidden and marked as deleted. This means it is easy to retrieve any email deleted in error. Compacting creates a copy of the file and then scan the file for those 'marked as deleted' emails, it ignores those sections and then resaves the file. This cleans up the file and recovers space.

If the file has any corruption then it is possible for those markers to be unreadible or undetected if missing. Whilst there are many reasons why any file can become corrupted, a lack of maintenance eg: regular compacting can be a cause, but so can AV products scanning files and attempting fixes.

I would advise that you keep mbox files down to a size which can be opened using a text editor program like Notepad++.

Good info on compacting, what it is, does and why it is important.

• http://kb.mozillazine.org/Compacting_folders
• https://support.mozilla.org/en-US/kb/compacting-folders

Like any file on a computer that is important, you would usually have a backup stored on an external harddrive etc.

The emails you are talking about are more than two years old, so is it possible those emails have been missing for a long time and you have only just discovered the problem?

As they are old emails, perhaps they were archived ?

Are you talking about pop or imap mail account folder or are you talking about 'Local folders' mail account?

Is this a gmail account ? If yes, then logon to webmaila ccount and see if those old emails are still lurking in the 'All Mail' folder. Gmail keeps everything in the 'All Mail' folder; received, sent or archived (that can also include emails with labels removed). Move them back into a suitable folder.

Do you have any backups of you Thundrebird profile name folder?

hi, the SENT folder has emails dating back until 2011 - the size is 275MB

the INBOX is 330MB and only showing until 2017

maybe not relevant but same system and same hard drive and same thunderbird running. - its a bell canada imap - no gmail.

the archive folder is empty as i don't perform that task.

the compact code needs to be verified to see if it is actually only compacting.....many users have reported the issue.

6 years of emails gone !!!! not very happy right now !

What is bell canadas retention policy on emails in IMAP accounts? When dealing with IMAP accounts local settings are overridden by the server. So if they clear out the inbox after say 30 days them that is how long mail stays there.

You might want to log into their web mail and see how far back your inbox goes. if it is 2017 then There is little if anything to be done in Thunderbird.

thanks Matt, you would think though that GET MESSAGES would be get them and copy them to your hard-drive... - its not VIEW ON SERVER (and let someone else decide what to do with your important stuff)? i know they were there before however.... and I also now that Thunderbird has messed up a few times on upgrades where all accounts had to be re-entered so this is probably where it failed and probably overwrote the folders..... for a free software - i guess i got what i paid for !!

its heartbreaking more than anything !!! I am going to try to scan the hard drive !!

What get messages does is ask he server if you have mail to get. For example Google will tell you no because you did not check the box for all old mail only mail from when you changed the settings.

Secondly IMAP is synchronised. I see folk in this forum lamenting the fact that they have done something on their phone or on a web server and inadvertently deleted all their mail. Unfortunately the software can not prevent the actions of those that do not know they do not know. IMAP mail is at bast a local cache of mail to speed up access. unfortunately people do not know that when they select the synchronized method that keeps their phone and tablet all in sync with the desktop.

When you are prompted for new accounts like a new user. Look straight at the anti virus program you have installed, or the streaming backup of the "cloud" synchronized folder the data is in. The correct resolution IS NOT to recreate accounts. Note that adding an account again in Thunderbird does not overwrite anything and if you are being asked for setup like a new user it is not even using the same profile folders.

Press the windows key +R Type %appdata%\thunderbird\profiles Press enter How many folders are listed in the file manager of the profiles folder?

Right click each pf them and select properties. How large is each folder?

i checked all the folders Matt, and they are gone... so here is a suggestion for Mozilla... a user doesn't care about POP or IMAP... a user doesn't care what setting mail servers have... all a user cares about is getting their email and having it dropped on the hard drive and accessible forever until it is explicitly deleted by the user. No need for archiving, no need for compacting, no need for a bunch of bloatware features that just cause confusion.... GET MESSAGE and it copies to my hard drive... no longer the email clients problem unless hard drive searched...

pretty simple ? and no lost emails. 6 yrs gone !!!

Matt, if mozilla doesnt show accounts after an upgrade most users will recreate because those are the functions presented. i have had many issues after upgrades... omg the infamous password issue... cant connect to server with password... which did not change but suddenly stops working after the upgrade and people going around in circles with all these whacky solutions.

anyways, thread should be closed. - Cause there is no solution !!!

re :a user doesn't care about POP or IMAP... They should because by default one keeps emails on computer and the other keeps emails on the server. These types of accounts are very different.

re: a user doesn't care what setting mail servers have... They should be aware of settings as ISP's etc may change server settings and authentication methods of accessing mail. If people change the server which hosts their website then they need to be aware that imap accounts may not have fully downloaded copies of emails and pointing to a new server may cause complete loss of access to emails.

re: all a user cares about is getting their email and having it dropped on the hard drive and accessible forever until it is explicitly deleted by the user. They need to understand their choice of pop or imap set up, whether they are synchronising folders or not, whether they have actually downloaded emails or headers only and whether they have backups of their emails. They cannot rely on anything which only has one copy. Believe it or not computers can fail, they can die, hardrives can become defunct and unuseable and this may have nothing to do with any specific application they have downloaded to use including email clients. Servers also have their own limits, quotas, deletion policies etc.

re :No need for archiving, no need for compacting, Archiving is just a means of sorting out old stuff, basic house cleaning. In gmail accounts, it just means removing all labels so email is only stored in the original 'All Mail' folder on server. It is also a means of reducing file size on currently in use files. It can also improve performance.

I've already explained compacting folders or expunging an imap Inbox is vital to maintain files.

Just because you see 'folders' with emails in them as a standard UI view, it does not mean this is how those emails are actually stored.

An mbox file is like a single document. Imagine this for your 'Inbox' mbox file: A single word document - one file - you compose the contents in paragraphs to make it easier to read. Now imagine each paragraph is actually an email. As each email is downloaded, it is written to that one file in the order downloaded, so the oldest is at the top. Now, as you read through your document, you may choose to delete certain paragraphs, but instead of deleting them, you just mark them ready for deletion; say you change all the font colour to red because at this point you may change your mind. This is like choosing to delete the 'paragraph emails', so Thunderbird marks them as ready for deletion and hides them from view, but they are still there because you may change your mind.

As you can easilly imagine, that single file over time is becoming large and messy. It is using space it really does not need to be using. Now you can leave it as it is and let it get larger over time and risk corruption of the file or you can keep it tidy and remove those 'red paragraphs' on a regular basis and reduce the likelihood of corruption and loss of file data.

If the contents of that file are important, you can create backups of that file, just in case the computer dies or the file gets corrupted or an Anti-Virus product scans a file and chooses to quarrantine it / fix it etc etc. A complete loss of a file can be because an AV product 'fixed' a file as they have no idea that the file is more than one email.

In your case, it would seem you have not performed any backups, so perhaps you accepted the risk or maybe those files were not that important, I have no idea what your reasoning was for not having a backup after all you are talking about years of no backups.

Therefore there is no solution in your particular case.

However, you could see this as a positive learning experience. You may have learned how files work; that emails are not necessarilly stored on your computer and that basic maintenance of files is advised and regular backups to an external drive is advisable if the information is important.

At this point, I would suggest you move forward with a view that you have gained some knowledge. Synchronise folders for offline use and get full copies of all emails downloaded. Then in offline mode, check you really can read various samples of emails in various folder to be sure that full copies are downloaded. Then exit Thunderbird and create a backup of your profile name folder. The easiest way is to copy the 'Thunderbird' folder in this location - assuming you have not moved anything from the default setup - and paste it onto another hardrive or usb drive of suitable size. Then you will have a copy of everything including address books, preferences and 'profiles.ini' file.

• C:\Users\<Windows user name>\AppData\Roaming\Thunderbird\

More helpful info on imap synchronising and profile:

• https://support.mozilla.org/en-US/kb/imap-synchronization
• http://kb.mozillazine.org/Profile_folder_-_Thunderbird
• https://support.mozilla.org/en-US/kb/profiles-where-thunderbird-stores-user-data

Additional info which you may find helpful. When creating a backup, you should exit Thunderbird first.

If you need to store emails on your computer which are not linked to the imap mail account or need to move emails off server to increase your quota, you can copy emails into a folder in the 'Local Folders' mail account before deleting from imap account. But always check you have copied full downloads and not just headers by going into offline mode. If you can read emails in offline mode then you have full copies.

Sorry Toad-Hall, i would disagree. - most users just want to read the email and have it somewhere where they can see it again if they need to... this has nothing to do with computer failure.... it's just having the file on your drive.... I know of no ISP that will keep your emails forever. - people don't care what ISPs do... nor do most people have the time to worry about a bunch of nonsense functions...

most of us jest need get email, auto saved as a file, read email. done. need email again, search email files, thanks !!!

if the folder is accessible and can simply be copied to another drive, then there is your backup. - no third party read MBOX add-ons, no cryptic MSF files, no headers.... blah blah blah... just an email file !! - no offline online modes going in circles, just to keep an email and read it again in the future !!!

anyways thanks for taking the time to reply....

In Windows, there is an auto folder for MUSIC,PICTURES, DOWNLOADS, DOCUMENTS, and there should be one for EMAILS where all email clients just auto save it there. - this is out of scope of our discussion but really - its 2019 and users have to worry about technical stuff for emails. this can easily be programmed in today's day and age !!

cheers

KeithEmail said

Matt, if mozilla doesnt show accounts after an upgrade most users will recreate because those are the functions presented. i have had many issues after upgrades... omg the infamous password issue... cant connect to server with password... which did not change but suddenly stops working after the upgrade and people going around in circles with all these whacky solutions.

I can only offer one bit of advice on all that. Get rid of the rubbish anti virus program you have and then you will not get the whacky errors and will not have to complain. I am almost like a rabid dog when Norton products are mentioned and my smile disappears when someone says Mcafee they have not release a non Thunderbird stopping version since 2012 when they created their new "heuristics engine"

KeithEmail said

In Windows, there is an auto folder for MUSIC,PICTURES, DOWNLOADS, DOCUMENTS, and there should be one for EMAILS where all email clients just auto save it there. -

That is a discussion you will need to have with Microsoft. You might also want to involve the internet engineering task force as there is not standard file format for emails. It is all good to have ideas on how things should be, and if you are capable you can make them so. Personally I have to just get on with the realities.

It could also be argued that there is a standard location for emails. the users appdata folder. I have a number of clients email stored there, not just Thunderbird's and I did not specify a storage location.

this is out of scope of our discussion but really - its 2019 and users have to worry about technical stuff for emails. this can easily be programmed in today's day and age !! cheers

You might be right. So why is there a sticker in the filler cap of your car that says unleaded only or Diesel only. Because people are ignorant of what they need to do and their ignorance can be exceedingly expensive to recover from.