Go ahead and delete that "recovered" folder, and there is also going to be an .OfflineCache folder that needs to be removed.  Note the period at the beginning of the file name; you will either need to show invisible files or use Terminal to delete that folder.

This most often happens when an unsuitable large file is attached to a message.  With GMail for example, any attachment over 20MB will be rejected.  Mail sees the rejection by the mail server and tries to recover from it by sending the message again.  Over time, these half-attempts to send mail stack up and start using all your drive space.

If you want a quick and easy way around the problem, remove the account in Mail's preferences, then re-add it. This will discard the offline cache for the account and free up your mangled space, at the expense of having to re-download the real messages.

And in the future, don't sent huge attachments.  Use a specialized service like Dropbox instead.

How can I keep Mail.app's archive from becoming too big?
I would be interested to hear if anyone had recommendations for 2-player games that are particularly suitable for playing while travelling on trains.  (I ask this as someone who mostly enjoys games like Carcassonne, Power Grid, Agricola, Pandemic, etc. around the table at home.)  To be specific, the things that I think are important properties for these games are:


Needing minimal table space.  Most trains have a small table you could use, but not much more.
Being quiet to play, so that other passengers won't be disturbed.  For example, I imagine that games that involve repeatedly rolling dice wouldn't be appreciated.
Packing down small, so that they don't take up much luggage space.
Not requiring batteries or a power socket.  (I appreciate that an iPhone or a Nintendo DS for each player might be a good solution more generally, but it's not what I'm after in this case.)
Not being so delicate to arrange that motion from the train will unduly disrupt the play.


I think it would be best to recommend one game (or class of games) per answer, if that's appropriate, and explain why you think it's particularly suitable.  (Incidentally, I've read the guidance on good questions about game recommendations and hope this question meets the criteria.)

Update: Thanks for so many excellent suggestions - we certainly won't be short of games for our next long train journey :)

Update 2: Unfortunately, I can't really playtest this many great games in any reasonable time period, so I'm going to accept the top-voted answer (Cribbage) and try out the others as soon as I can.  Thanks again...
