Syncing with multiple computers.

That's not necessarily a problem: Dropbox can upload only the changed bytes of a file. One big initial sync would of course be needed.

I've been thinking of trying it, either with Dropbox or Microsofts Mesh, but I worry that if I forget to close the email client on one of the computers it might corrupt the data...

User error :-P
Maybe Dropbox does even upload changes as the occur, why should it wait till the app is closed. I think an internal sync service would be more vulnurable because it would sync only at startup and shutdown of Postbox. At least that's how various thunderbird sync addons work.
Also: How important is it really to have all settings/filters and stuff synced to the second? Syncing mail is more important and that's what IMAP is for :-)

I don't think dropbox would work, unless you could specify specific file locations for different things in postbox, which is a bad idea. You don't want it to sync your mail and such,, just the settings.

I haven't tried creating aliases to do syncing with dropbox, but, i have a feeling that would end badly.

Oh right, I forgot Dropbox can only sync its specific folder "My Dropbox". They are planning to allow other folders soon. The you could tell dropbox to sync your entire profile folder. Or, make Dropbox portable yourself and put it into "My Dropbox" :-) Nonetheless it would be very nice to integrate a little sync function (esp. for adressbook and calendar) into Postbox itself :-) Pleeeaaase!

Something along the lines of Foxmarks (www.foxmarks.com) would work well... maybe Postbox can partner with them or get them to write a plug-in that allows syncing... would be especially useful for syncing topic categories.

Postmarks, hahaha! Honestly Foxmarks is really awesome, works like a charm. I would definitely like to see them extend their product range to Postbox, Thunderbird and even offer more functions for Firefox :-)

Here is a possible solution. If you are using Postbox and want to sync it to two machines. I suggest the following. Use IMAP, Exchange or any other email program that will sync to the server so you don't need to worry about syncing your msgs. Second, you setup dropbox and use symbolic links to sync the settings file for Postbox between the two machines:

Use the ln command, for example:

ln -s /path/to/desired-folder ~/Dropbox/desired-folder

This works with files too:

ln -s /path/to/desired-file ~/Dropbox/desired-file

Another easy way to do this with Terminal is type the ln -s part, then from Finder drag the folder/file that you want into the Terminal window then drag the Dropbox folder and hit return.

Note that an Alias file or folder does not work.

That way...your settings are syncing and thats all you really need! How does that sound?
--update

Just looking at the postbox files and it seems like they are pretty jumbled together.. I suggest to the developers that they organize the settings into specific folders so we can find a sync work around until the official (ehem) one comes out.

Great program ... best email I have used since Squirrel in 93

I would be worried about what would happen if postbox was opened on multiple computers using drop box.

Also, postbox uses the mozilla profile style where profiles are random. So, if you sync EVERYTHING in your profile.ini and profile directories it might work.

But if you have it open on 2 or 3 computers it might create a situation where the files are modified on 2 computers at about the same time (laptop open next to a desktop).

Perhaps store the synchronization information in a hidden IMAP folder? Or on in webdav?