Milton,

I'm sorry, but I believe your partner may be incorrect. The only information I see in RFC822 that regards the length of the headers is the following:

3.4.8.  FOLDING LONG HEADER FIELDS

        Each header field may be represented on exactly one line  con-
        sisting  of the name of the field and its body, and terminated
        by a CRLF; this is what the parser sees.  For readability, the
        field-body  portion of long header fields may be "folded" onto
        multiple lines of the actual field.  "Long" is commonly inter-
        preted  to  mean greater than 65 or 72 characters.  The former
        length serves as a limit, when the message is to be viewed  on
        most  simple terminals which use simple display software; how-
        ever, the limit is not imposed by this standard.

In bold, I've highlighted the words that state that the lines may be folded for readability on older terminals. Please do note that the RFC is dated 1982, so we're already talking "simple" terminals per the standards available 25 years ago :-)

In italics I highlighted the section that states there is not limit set by this RFC.

As a reference, in RFC2821, there is instead defined a clear limit of 1,000 on the maximum length of any line in the email (SpamFilter's header is below that threshold), and the relevant section is:

text line
      The maximum total length of a text line including the <CRLF> is
      1000 characters (not counting the leading dot duplicated for
      transparency).  This number may be increased by the use of SMTP
      Service Extensions.

Milton,

Edited by Desperado - 15 January 2008 at 12:34pm