Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!decwrl!ucbvax!TRANSARC.COM!Craig_Everhart From: Craig_Everhart@TRANSARC.COM Newsgroups: comp.protocols.tcp-ip Subject: Re: Is underscore legal in the local-part of an address? Message-ID: <0afOwPL0BwwOMW_Hxb@transarc.com> Date: 25 Jul 90 14:39:23 GMT References: Sender: daemon@ucbvax.BERKELEY.EDU Lines: 25 RFC822 says that periods are legal but somewhat restricted in local-parts. You can't legally have two periods following each other, and you can't have the local-part begin or end with a period. Thus, joe.blow@toaster.com is legal, while joe..blow@toaster.com jane.smith.jr.@toaster.com are not. (The local-part is made up of a sequence of period-separated ``word''s, and an unquoted ``word'' may not contain a period.) As to the ``phrase'' that precedes a route-addr, the syntax is slightly different (a space-separated sequence of ``word''s), and a period anywhere in it needs to be quoted. This is traditionally done by quoting the entire phrase text. Thus, Joe Blow "Jane Smith Jr." are legal, but Jane X. Smith is not. Then again, your programmer who believed that all other mailer implementations strictly follow RFC 822 was a bit naive. ``Liberal in what you accept, conservative in what you generate.'' Craig