JCURRAN%UMASS.BITNET@WISCVM.ARPA (12/10/85)
I have seen several user-extension fields that lack the "X-" prefix (making them simply extension-fields; subject to being redefined) in hopes that other sites might employ them. Since some extension fields (user or other) involved the processing of incoming mail, it only makes sense for a site which supports such fields to inform others so that the incoming mail it recieves may contain such information. If, for example, a mail system supported field yyyyy, how would/could it tell other mail system programmers about it? Is any agent maintaining a lists of'commonly used rfc822 extension fields? -- John Curran -- Umass/Amherst