On 12 Jan 2006, at 16:33, net kat wrote: > I'm considering migrating from Mail.app to an open source app, such > as thunderbird, or mozilla mail. > Important factors to me are... I'm interested to know what's wrong with Mail.app for your purposes. I don't use its filters but they seem OK to me, and its files are stored in a standard *nix format (that should open natively in Thunderbird, I think). If you ask because you also want to access your mail on a PC then the way to do it is probably NOT to carry all the message files around on an external drive. An IMAP account would be FAR better. Stroller.