Question regarding symbols in name resolution

Bill Larson wllarso at swcp.com
Thu Apr 19 22:42:24 UTC 2001


As Kevin said, "companyxyz_smtp at xyz.com" is an acceptable email address,
but this is cannot be a server name that includes an "@" .

Now, the problem may be simpler than what was originally suggested.  Maybe
the problem is a simple "typo".  This may be the difference of "companyxyz"
and "company_xyz", as the original poster identified both.

Bill Larson

> Well, first of all, the part of an email address that precedes the @ is not a
> DNS name. Underscores are legal in the *mailbox* part of an SMTP address. The
> company abc folks apparently don't understand the composition of an
> SMTP address.
> 
> More generally, underscores are only illegal in "hostnames". Not everything in
> DNS is necessarily something that would be used in a hostname. SRV records, for
> instance, have owner names with underscores in them; in fact, this was done
> deliberately to distinguish them from hostnames.
> 
> 
> - Kevin
> 
> Patrick McAllister wrote:
> 
> > I apologize for what is not doubt a very basic question. I think I already
> > know the answer to this but would definitely like a second opinion.
> >
> > As I understand it, certain symbols are "forbidden" in DNS, one of which is
> > the underscore. My problem is this, I have a client who has a mail server
> > they have named companyxyz_smtp at xyz.com. They actually seem to get mail fine
> > from everyone except one organization. This one organization, say company
> > abc, claims they cannot send mail to company_xyz because of the underscore.
> >
> > Is an underscore indeed a "forbidden" character? If so how is it no one
> > except company abc seems to be having these issues.
> >
> > Thanks in advance, flame away if need be to me at tomservo at erols.com!
> 
> 
> 
> 
> 



More information about the bind-users mailing list