How to set up 'Archive Options:

When setting up 'Archive Options', I would suggest you use Monthly (if you get a lot of emails per month) and keep existing folder structure. Tools > Account Settings > Copies & Folders for the mail account.

this will need to be done for each mail account

All info here with helpful images:

• https://support.mozilla.org/en-US/kb/archived-messages

Choosing a batch of emails to archive: Select a folder and sort by Date then select/click on the first email you wish to archive hold down Shift key and click on the last email All emails in between will become highlighted and appear as 'conversations' in the Message Pane. click on 'Archive' button.

Archiving a single email: select the email and click on the 'Archive' button in the header area.

Emails will be stored in the 'Archives' folder, which will appear in the Folder Pane, one for each mail account. These emails are still in your Profile and still accessible and so need to be included in any backup.

I would suggest you consider archiving anything not received this year as this will reduce your file size considerably and therefore use less memory when opening folders.

Much appreciated Toad. However the archiving seems to work by creating folders for each year e.g. 2008,2009 etc. but this is not suitable for me. I need to archive by Client name e.g. Acme, Brown, Carter.. Is there a way to do that ? I tried to make a complete copy of a folder, as an archive, and then just delete the newer messages which will stay in the main folder, where the old ones would be deleted. This didn't work as copying whole folders doesn't seem to be allowed.

Assuming you have all your emails pre-organised in folders called : Acme, Brown, Carter etc

When you created the Archive options, if you had selected yearly and retain folder structure, then it would be archived as follows:

> Archives > > 2008 > > > > Acme > > > > Brown > > > > Carter > > 2009 > > > > Acme > > > > Brown > > > > Carter

If you selected monthly and retain folder structure: > Archives > > 2008 > > > >2008-01 > > > > > >Acme > > > > > >Brown > > > > > >Carter

This would mean that all the Acme, Brown, Carter folders would be in Archives, but the size of the folder will be smaller because it is divided by year, or even smaller if monthly is used. (If you only have a few emails per month then yearly would be ok). So, if you have not organised your emails into eg: Acme, Brown, Carter folders, then do this first, then when you Archive them they will still be located under Archives in a folder of that name, so easy to locate.

Folders containing emails that you see in the Folder Pane are in reality mbox files - not folders, and these files are stored in your profile folder. Each file has emails stored one after the other, in the order they were downloaded, so emails are not stored in individual files. If you accessed your Profile folder and opened one of these mbox files using 'Notepad', you would see one huge long document. Each mbox file also has a .msf indexing file. Large documents carry a greater risk, if something goes wrong, you could lose a lot of emails. The point of using the auto archiving is that this will sub divide those large files into smaller files and therefore carry less overall risk per file and use less memory when accessing.

http://kb.mozillazine.org/Performance_-_Thunderbird Thunderbird loads a folder's *.msf file into memory whenever it opens the folder. By default it keeps up to 30 *.msf files open for 5 minutes (and their contents in memory), unless they are "special" folders, which it never closes. It loads the inbox.msf file for every account on startup. The best way to minimize the amount of memory used is to archive messages you have already read or otherwise no longer need in Inbox into folders that you rarely open. Moving a message to an archive folder opens it, so consider archiving messages by year and month rather than yearly so that the archive being used doesn't get excessively large.

If you choose to not use Archive options and instead manually created Acme, Brown, Carter folders in the Archives folder,it means you will have to manually move emails into those folders. In which case, you will just be creating new large folders, which will get larger everytime you move an email. As they are Archive folders then they will end up with even more emails than you currently have, so I'm sure you can imagine what could happen over time. With Archived emails you need to consider the long term.

At the end of the day the choice is yours, but at least you now have some information to make an informed choice.

Again thanks Toad for the detailed reply, I feel humbled. I understand what you say. I had hoped to not have the years at all, just the names Acme, Brown, Carter folders in the archive and each of these have a time continuum of messages without being in year folders. As a compromise I could live with year headings under the name headings, not vice versa. Is that possible ?