Re: [exim] Rejecting non-RFC compliant email addresses?

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Author: Philip Hazel
Date:  
To: Gregg Berkholtz
CC: exim-users
Subject: Re: [exim] Rejecting non-RFC compliant email addresses?
On Wed, 8 Jun 2005, Gregg Berkholtz wrote:

> I've begun receiving emails with quotes or slashes in the recipient's
> address, and my exim daemon/config (v3.35) is accepting the addresses as
> valid - to a point... My understanding was that such characters, within
> email addresses, should not be treated as valid.


Wrong. See RFC 2822. Almost anything is permitted in a local part if
correctly quoted. However, slashes do NOT have to be quoted. The special
characters that do have to be quoted are

( ) < > [ ] : ; @ \ "

and strictly, you can't have two dots in succession without quoting.

Note that some recipient local parts quite legitimately contain
non-alphanumeric characters. In the days of X.400 interworking,
addresses such as

/somex.400address@???

were common. Consider also

o'reilly@???

People also use + - ? / = for special kinds of internal delimiter in
their local parts. So you have to be a bit careful when thinking about
this.


-- 
Philip Hazel            University of Cambridge Computing Service,
ph10@???      Cambridge, England. Phone: +44 1223 334714.
Get the Exim 4 book:    http://www.uit.co.uk/exim-book