ietf-asrg
[Top] [All Lists]

Re: [Asrg] Some data on the validity of MAIL FROM addresses

2003-05-20 11:07:12
At 01:34 PM 5/20/2003 +0100, Jon Kyme wrote:

>Folks, the email operations world has increasingly moved away from
>real-time processing of SMTP data.
>

A colleague has just drawn my attention to the relevant part of rfc2505
(BCP 30) - for completeness here it is:

<quote>
1.5. Where to block spam, in SMTP, in RFC822 or in the UA

   Our basic assumption is that refuse/accept is handled at the SMTP
   layer and that an MTA that decides to refuse a message should do so
   while still in the SMTP dialogue. First, this means that we do not
   have to store a copy of a message we later decide to refuse and
   second, our responsibility for that message is low or none - since we
   have not yet read it in, we leave it to the sender to handle the
   error.

</quote>

See RFC 2821, section 3.1.:

---snip----
   However, in practice, some servers do not perform recipient
   verification until after the message text is received.  These servers
   SHOULD treat a failure for one or more recipients as a "subsequent
   failure" and return a mail message as discussed in section 6.
---snip----

Even thought it might be recommended to do processing in real-time, in practice many systems do not and will not. We must be take that into account.
_______________________________________________
Asrg mailing list
Asrg(_at_)ietf(_dot_)org
https://www1.ietf.org/mailman/listinfo/asrg



<Prev in Thread] Current Thread [Next in Thread>