[imp] Headers parsing

[Arminas]

Hello list,

I'm not sure if its correct list, but it would be great if anyone
could give an explanation about headers parsing. I'm using IMAP
connection. It's interesting for me because in some cases messages is
not displayed properly. F.e. there is no subject shown, but field
"Subject: example example example" exists when looking emails source.
Or, in worst cases, all inbox is not shown if there is one mail's
(which is in the current view) header damaged. So maybe there is a
list of headers which is recognized so I could add to the list some
headers by myself? I could forward a couple examples (emails) but im
not sure if it would help.

ps. I was looking these messages through thunderbird and some other
clients and it worked fine.

Thanks,
Arminas