Status and X-UIDL headers

[Julian M Catchen <julian catchen org>]

Hey Everyone,

I was hoping that someone on this list could tell me where the "Status" 
and "X-UIDL" headers are defined in the standards documents?  Are these 
defined or mentioned in an RFC somewhere, or do most POP servers just use 
them?  I realize the "X" in "X-UIDL" means it is *not* standard, but it 
seems to be used in too many places to be that unstandardized.  Also,  I 
was wondering if anyone can tell me to what extent Balsa makes use of 
them.  Does Balsa use these to determine if a message has been read?

I am looking to use these headers in a mail project I am working on, but 
don't want to unless they are pretty reliable across implementations.

Thanks in advance for any help,

julian