On Mon, 25 Mar 2002, at 5:49pm, Toni, Randy wrote: > Seems to me that the structure of a mail server hostname can contain an > underscore (or a period, etc.) as part of the "atom" or "dot-atom" > component in the "local-part" of the "addr-spec" ...
The "local-part" of an "addr-spec" (address specification) is the part to the *left* of the at-sign (e.g., "user" in "[EMAIL PROTECTED]"). I think you mean the "domain" part ("domain.com" in the above). The "domain" part is a domain name, easily enough. RFC-2822 references several other Internet standards on that: STD-3, STD-13, and STD-14. RFC-1123, "Requirements for Internet Hosts -- Application and Support", included by STD-3, Section 2.1, states that "The syntax of a legal Internet host name was specified in RFC-952." RFC-952, "DOD Internet Host Table Specification", Section 3, states "A 'name' (Net, Host, Gateway, or Domain name) is a text string up to 24 characters drawn from the alphabet (A-Z), digits (0-9), minus sign (-), and period (.)." Underscores are not allowed in an Internet host name. -- Ben Scott <[EMAIL PROTECTED]> | The opinions expressed in this message are those of the author and do not | | necessarily represent the views or policy of any other person, entity or | | organization. All information is provided without warranty of any kind. | List Charter and FAQ at: http://www.sunbelt-software.com/exchange_list_charter.htm