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Re: [Asrg] 6. Proposals - AMTP (rev 01) - MPC

2003-10-02 02:24:34
At 2:57 AM -0500 2003/10/02, Bill Weinman wrote:

 Why would backup servers have different MPC than the servers they back up?
 Because they aren't always provided by the same company.

 That doesn't mean they must have different preemptive MPC values. There
 are a number of ways to deal with this: use a least-restrictive common
 setting for the EHLO reply MPC value; bind to a particular IP addresses
 for your back up server. That's off the top of my head.

If you don't control the other machine, how are you going to control what they use for MPC? If you don't control the anti-spam settings for the other machine, how are you going to control what spam gets into your system?

 The EHLO reply preemptive MPC feature is not for everyone. I'm assuming
 most large ISPs will not use it. But it's an excellent solution for
 corporate mail servers where the corporation wants to control costs and
 set company-wide policies.

Homogenous network environments where the same policy is applied to everyone is not going to be a particularly large subset of users.

                             But I expect many ISPs to have various
 settings available for their users to set on a recipient-specific
 basis. Like they do now with spam filters.

Which implies that we need some sort of mechanism to be able to communicate this information later in the SMTP dialog.

Moreover, if we had that, and could advertise that information via EHLO, everyone would be better off -- homogenous network environments applying the same policy to everyone would be able to continue to do so, while heterogeneous network environments with per-user control over these features would also be able to make use of this functionality.

Of course, this doesn't solve the problem with backup MXes. Or senders that ignore this feature because it is inconvenient.

Brad Knowles, <brad(_dot_)knowles(_at_)skynet(_dot_)be>

"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety."
    -Benjamin Franklin, Historical Review of Pennsylvania.

GCS/IT d+(-) s:+(++)>: a C++(+++)$ UMBSHI++++$ P+>++ L+ !E-(---) W+++(--) N+
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