Re: [exim] dot at the end of a local part

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Author: ROGERS Richard
Date:  
To: Phil Chambers, exim-users
Subject: Re: [exim] dot at the end of a local part
exim-users-bounces@??? wrote:
> I have just seen examples of mail with a sender address whith the
> local part ending with a dot:
>
> <MikeG.@continentalways.com>
>
> (I was surprised to see Exchange reject this because it is willing to
> accept all sorts of rubbish in addresses without complaint!)
>
> Exim seems to allow this through despite it not conforming to
> RFC2822. As I read it:
>
> local-part      =       dot-atom / quoted-string / obs-local-part

>
> dot-atom        =       [CFWS] dot-atom-text [CFWS]
> dot-atom-text   =       1*atext *("." 1*atext)

>
> Its not quoted-string
>
> obs-local-part  =       word *("." word)
> word            =       atom / quoted-string
> atom            =       [CFWS] 1*atext [CFWS]
> atext does not include "."

>
>
> I can put in a specific ACL to reject this but it really
> aught to be picked up
> by Exim at a more fundamental level.
>
> I am running exim-4.68 and I don't see a change in the change-log for
> 4.69.
>
> Phil.
> ---------------------------------------
> Phil Chambers (postmaster@???)
> University of Exeter



I added the following ACLs to our configs to avoid passing messages
through to Exchange that it would then reject, leading to a bounce. I
agree, it might be nice if there were a "strict address checking" option
incorporated into Exim that would do this job. (For our purposes, an
alternative would be to use the envelope sender address in the call
forward that we use to verify the recipient, but I don't think that is
currently an option either, is it?)

regards

Richard

# Deny any message whose envelope sender address has consecutive dots
(illegal)
# (do this for all messages irrespective of recipient's spam preference
#  because Exchange will reject them if we attempt to deliver)
deny senders = ^.*[.][.]
     message = Sender address syntax error (consecutive dots):
$sender_address


# Deny any message whose envelope sender address starts with a dot
(illegal)
# (do this for all messages irrespective of recipient's spam preference
#  because Exchange will reject them if we attempt to deliver)
deny senders = ^[.]
     message = Sender address syntax error (leading dot):
$sender_address


# Deny any message whose envelope sender address ends with a dot
(illegal)
# (do this for all messages irrespective of recipient's spam preference
#  because Exchange will reject them if we attempt to deliver)
deny senders = ^.*[.][@]
     message = Sender address syntax error (trailing dot):
$sender_address


# Deny any message whose envelope sender address is ""@???
# (do this for all messages irrespective of recipient's spam preference
#  because Exchange will reject them if we attempt to deliver)
deny senders = ^["]["][@]
     message = Sender address syntax error: $sender_address


# Deny any message whose envelope sender address contains 8-bit
characters,
# a violation of RFC2821 and only done by spammers.
# (do this for all messages irrespective of recipient's spam preference
#  because Exchange will reject them if we attempt to deliver)
deny senders = \N^[^@]*[\x80-\xFF][^@]*\@.*\N
     message = Sender address syntax error (8 bit characters):
$sender_address




--
Richard Rogers
IT Development and Innovation Manager
Information Services, Staffordshire University


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