I've been using Thunderbird for years without issues with 20+ pop3 accounts. I'm moving over to imap which will enable me to keep copies of the emails locally and on the server whilst keeping everthing synchronised.

However I'm looking for the best way to manage multiple imap accounts on Thunderbird.

Currently I have a filter that copies all the emails into a central inbox and into seperate local folders. The reason for this is I go through my inbox daily and delete all emails that don't require any action. I move any emails that require action to my "action" imap account folder. This way I can syncronise all the emails that require action across multiple computers (and mobile devices). This technique is my implemantion of the GTD or Getting things Done philosophy.

I also copy over each email into seperate local folders. The reason I do this is just in case any emails on the imap accounts get deleted, or something drastic happens on the server which means I lose all the emails. My business partner has access to some of these emails and still uses pop3 (with "leave copy on server" checked), but I know sometimes Thunderbird can still delete emails off the server sometimes.

The problem with the above is that thunderbird gives me the dreaded error dialogue saying that the emails cannot be filtered due to another process.

I find the folder list in Thunderbird hard to manage. Here is a screenshot of part of my folder list- as you can see it's a bit of a complicated list and not easy to manage:

What would be the best way of me managing multiple imap accounts whilst allowing me to have copies put in a central folder and emails in local folders?

It would be useful if people think this is necessary, as perhaps there is a betterway?

How do people manage multiple imap accounts in a way that allows them to keep on top of actionable emails?

I'd be interested in how others manage this. I've never used the Thunderbird-based client "Postbox", does this handle multiple imaps better?