SMTP authentication for broadband providers

Suresh Ramasubramanian suresh at outblaze.com
Thu Feb 12 01:48:18 UTC 2004


Will Yardley wrote:

> My understanding is that in most cases, providers are blocking port 25
> outbound to prevent direct to MX spamming from their customers' machines

If you do that, please put in a corresponding ACL to block port 25 
inbound _and_ outbound.

Otherwise, you just might get bitten by something like spoofed source 
routing, as several providers have found out in the past.

	srs



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