ietf-smtp
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Re: RFC2821bis-01 - number of message transactions per connection ?

2007-03-29 04:48:00

Matti Aarnio wrote:

Some may have noticed a trend of rejecting emails when there are more than
some small number of messages sent over same network connection stream ?

The RFC 821 didn't state anything explicite about it, but indirectly permits
it.  As I recall, RFC 2821 does not say anything explicite either.
Could 2821bis  say something ?

  There is _no_ limit on number of messages sent over established SMTP
  protocol connection.  Those receivers that want to limit it are expected
  not to loose messages from high-volume email lists that often optimize
  things by sending accumulated queue over the established connection.

I respectively have to vote a -1 on this. Limits are local policy considerations and the specs can in no way dictate a _no_ limit operation on receivers.

Could there be some EHLO-response telling that the message
> transaction count is limited at the receiving server ?

How does that relate to # of RCPT TO allowed which is currently restricted by local policies and typically a local policy for authorized sessions different from a local policy for anonymous sessions?

And even if there was a limit, whats to stop you from breaking up your "small amount" of bulk mail into multiple transactions or begin to send the "small amount" one message at a time?

In my view, if you are sending bulk mail, and you are restricted, then you are more than likely an unknown, or non-authorized/non-authenticated session. If you are a trusted source, most systems are not going to place a limit on you.

--
HLS