For the past couple of months I’ve been using Thunderbird for my email, finally replacing Eudora. All in all, well worth the transition, especially with the way it handles spam (and in particular, the RegEx plugin FiltaQuilla).

But lately, one message has been bugging me:

The messages could not be filtered to folder ‘Trash’ because another operation is in progress.

Needless to say, since my emails weren’t filtered, I had to do the work manually – very annoying.

A bit of research later, and the solution was simple: I had under the advice of another website reduced my auto-compaction rules to 1 meg. So as email came in, it triggered automatic compaction, which prevented the filtering. Bumped it up to 10meg, and problem went away.

Here’s how:

• Go to menu Tools; Options; and tab ‘Network & Disk Space’
• Increase the amount for “Compact all folders when it will…” to at least 10 meg.
• …or better yet, uncheck the box, and be prompted to manually compact.

That’s it!