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From: rickert@mp.cs.niu.edu (Neil Rickert)
Newsgroups: comp.mail.misc
Subject: Re: PLEASE NOTE: CS is an official top level domain now!!!
Message-ID: <1990Dec21.044229.6615@mp.cs.niu.edu>
Date: 21 Dec 90 04:42:29 GMT
References: <1990Dec20.212439.4507@cunixf.cc.columbia.edu> <1990Dec20.232606.1302@mp.cs.niu.edu> <CKD.90Dec20220406@bucsd.bu.edu>
Organization: Northern Illinois University
Lines: 42

In article <CKD.90Dec20220406@bucsd.bu.edu> ckd@cs.bu.edu (Christopher Davis) writes:
>Neil> rickert@mp.cs.niu.edu (Neil Rickert) writes:
>
>Neil>  The only reliable approach is to qualify in the local domain only if the
>Neil> domain name is completely unqualified (no periods).  Otherwise treat the
>Neil> name as already fully qualified.  In other words, don't use RES_DNSRCH
>Neil> in domain lookups.
>
>Assuming that your mailer is broken in this manner, you can always
>"anchor" the root domain in such a way as to keep it from completing to
>the local domain.
>
>(For example, one of the local machines is named "bu.edu"; this
>sometimes tries to resolve to "bu.edu.bu.edu" instead.  I just use
>"bu.edu." (note the extra period to anchor the root)--and all is well.
>

Please note the following excerpt from RFC1123, which specifically complains
about adding a trailing period as an error.

 Moreover it is not reliable, as it may seriously intefere with address
parsing, depending on the exact algorithms used.

      5.2.18  Common Address Formatting Errors: RFC-822 Section 6.1

         Errors in formatting or parsing 822 addresses are unfortunately
         common.  This section mentions only the most common errors.  A
         User Agent MUST accept all valid RFC-822 address formats, and
         MUST NOT generate illegal address syntax.

.....

         o    Some systems over-qualify domain names by adding a
              trailing dot to some or all domain names in addresses or
              message-ids.  This violates RFC-822 syntax.


-- 
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  Neil W. Rickert, Computer Science               <rickert@cs.niu.edu>
  Northern Illinois Univ.
  DeKalb, IL 60115                                   +1-815-753-6940