• 'Menu icon' > 'Message Filter' > 'Message Filter'
• Filter for: choose mail account name
• click on 'New'
• Give filter a suitable name
• Select 'Manually Run'

I suspect this next bit is where you are having an issue. select 'Match all of the following' - this means both parameters must be true for each email, so it is selecting email address AND before date This is ok if you only need to choose one email address, but not several.

select 'Match any of the following' - it means any of the parameters could be true, so it is selecting email address OR before date so this could end up selecting any email address if the before date matches the parameter.

I would suggest a workaround. In 'Address Book' Create a new address book and only put those specific email addresses in it. Then use that address book in the Filter.

select 'Match all of the following'

• 'From' and 'is in my address book' select the new address book
• click on small + sign to get another line
• 'Date' and 'is before' choose date

Perform these actions

• 'Move message to' and select the correct folder on account.
• click on OK

• Enable the filter
• select/highlight the filter
• Run selected filters on : choose the folder
• click on 'filter log' button
• select : 'Enable the filter log'
• click on 'Close'
• click on 'Run Now'

Yes - I think that will do it. Thanks!!

Maybe you can answer a related question: I'm not sure how the files are structured in mail. I'm using Yahoo - IMAP I think.

I'm going through this exercise to reduce the size of my inbox (which has thousands of emails in it). Will moving emails to subfolders help? I know it will reduce the number of emails in the inbox, but are all the emails in all the folders still kept in one big file? Or are they split up? If they're still in one big file, I won't be helping much. Is this why people archive? Would archiving allow me to back and delete?

If I move a folder to be a subfolder of another, is mail jumping through hoops to copy and pate emails in the middle of a large file or does it just rename files or set new pointers?

Thanks again. I can post this as a separate questions if that is more acceptable,

There is also https://addons.mozilla.org/en-us/thunderbird/addon/filtaquilla/

I loaded Filtaquilla (I think) but it didn't seem to change anything. Set preferences for search, too. It does say my version is too recent.

re: to reduce the size of my inbox (which has thousands of emails in it). Will moving emails to subfolders help?

Other folders and Subfolders are separate. It is a good idea to reduce email numbers in Inbox as this folder gets a lot of activity and is best kept as a folder for incoming unread / new mail or recent mail not yet sorted.

It is also less risky; if something should happen to Inbox and it contains a load of emails, the risk of loss of alot of mail maybe something not desirable.

Gmail do keep all emails in 'All Mail' folder, you get to see emails in other folders by setting 'labels' which are like tags. They faciltiate a more natural but virtual view of folders for the user. This means one email can appear in more than one folder. Deleting an email may only remove a label; it may not necessarilly delete the email from the 'All Mail' folder. Gmail also use 'All Mail' as the archive.

I'm not sure if Yahoo have the same system.

Please note that for imap mail accounts, moving emails to another folder on the server will not decrease the quota you use.

If you need to decrease the quota used on the server, you would need to delete emails. If you need to keep copies of emails, create some new folders in 'Local Folders' mail account, then synchronise imap folders for offline use, then in Offline mode (If moving a load of emails I suggest offline mode as it stops synchronisation of folders whilst copying emails), select emails and use right click 'Copy to' and select a folder in 'Local Folders' mail account. Once you are sure you have readible copies in Local Folders mail account, you can delete the copies in the imap folders. Then compact the imap folder to remove all 'marked as deleted' but hidden emails. When you go back into 'online' mode synchronisation will occur and those emails will get removed from server thus increasing your quota.

If you keep emails in 'Local Folders' then you should make periodic backups as they maybe your only copy, but I would synchronise folders for offline use to get copies in Thunderbird profile and perform a backup regardless. Just in case you lose emails off server.