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Date: 12 Mar 1996 23:06:58 GMT
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From: djb@koobera.math.uic.edu (D. J. Bernstein)
To: drums@cs.utk.edu
Subject: Re: Message format document outline

> while there is no firm requirement that addresses in 822 be restricted
> to those that SMTP can handle, in practice, most 822 messages  will
> be transported over SMTP at some point in its path from sender to recipients.

So what? My MTA handles this correctly.

Sure, sendmail handles it incorrectly, but sendmail has a much deeper
problem---its \user convention for ignoring aliases. That backslash is
part of the _encoding_, not the _content_, of the address; see RFC 822,
section 3.4.1. When sendmail preserves the backslash over SMTP, it is
violating RFC 822, section 3.4.4.

Unless you're willing to change RFC 822's clear boundary between content
and encoding, you can't legalize sendmail's behavior.

Again, see ftp://koobera.math.uic.edu/pub/docs/1996-mail-errors.

---Dan