SMTP addresses in <>

[Seth Mattinen <sethm () rollernet us>]

I'm having a bit of an argument with a customer over the command syntax 
in RFC 2821 that shows command arguments for MAIL/RCPT commands in 
brackets, i.e.:

Path = "<" [ A-d-l ":" ] Mailbox ">"
Mailbox = Local-part "@" Domain

Our mail servers reject connections that don't follow the RFC. Am I 
wrong to do this? This guy certainly thinks so, even after I've cited 
the RFC and appropriate section, his arguments is "even hotmail does not 
keep up the standards" and if we ignore them as well. Hotmail at least 
follows this rule... am I wrong to require the brackets?

~Seth