formail help

[Attila Csosz <csosz77@axelero.hu>]

Hi,

Which fields should I place at least to this list to get correct 
mailbox? I use the followings but I've got an error message in mutt 
"this is not a correct mailbox" (or similar)


in my .procmailrc

:0
*
| formail -k X From: -X Subject: >> inbox

Thanks
Attila