Over the last few weeks, I've noticed that Eudora was getting very sluggish, and would often tie itself up for minutes at a time. Seems I was keeping too much mail around for it to handle in any kind of reasonable way. I subscribe to a bunch of mailing lists, and get the all too typical spam load - so I receive well north of 300 emails per day. I hadn't deleted any mail since 2003, and Eudora was having trouble with folders that had tens of thousands of messages. So... I whacked all the older ones (after saving copies), and Eudora was back to its formerly snappy self.

Anyone know if Thunderbird is able to hold large amounts of mail without this issue?