I am curious about what network operators are doing with outbound SMTP traffic. In the past few weeks we have ran into over 10 providers, mostly local providers, which block outbound SMTP and require the users to go THOUGH their mail servers even though those servers are not responsible for the domains in question! I know other mail servers are blocking non-reversible mail, however, is this common? And more importantly, is this an acceptable practice? Most of our smaller ISPs that we support; we allow any outbound SMTP connection, however we do watch residential users for 5+ outbound SMTP connections at the same time. But if the ISP has their own mail servers, and users wish to relay though them, we basically tell them to use their mail server that they contract with. What is the best practice? ----------------------------------------------------------- Dennis Burgess, Mikrotik Certified Trainer Link Technologies, Inc -- Mikrotik & WISP Support Services Office: 314-735-0270 <tel:314-735-0270> Website: http://www.linktechs.net <http://www.linktechs.net/> LIVE On-Line Mikrotik Training <http://www.onlinemikrotiktraining.com/> - Author of "Learn RouterOS" <http://routerosbook.com/>