Hi,,, It seems this Microsoft of us is giving us problems almost everyday irrespective of being proactive!! To get to my point: I'm running Exchange Server 2007 in one of my clients, now the send from external partners get delivered after 30minutes or does not get delivered at all an the ndr to the sender report after a full one day: error as follows: "the following organization rejected your message: [exchangeip address],, #5.0.0 smtp; 5.4.7 - delivery expired (message too old, deafult timeoutError, delivery attempts 55" In the first instance i thought of domain or Ip blacklisted but none as sometimes mail can be delivered sooner than expected I need help here Shakoanem

Hi, It's not Microsoft's issue..I am sure that it is your configuration issue :) If your server's external ip doesn't matches you MX record and the corresponding A record then this may be the result. The name, forward and reverse DNS must match. Regards from www.windowsadmin.info

Hi You can do those checks at www.mxtoolbox.com to see if MX and A/PTR matchesJonas Andersson MCTS: Microsoft Exchange Server 2007/2010 | MCITP: EMA 2007/2010 | MCSE/MCSA Blog: http://www.testlabs.se/blog

Hi ManU I tend to slightly agree with you on the point of 'Server's external IP not matching MX record" However, i have checked mx record matching and believe they match as per my knowledge, please advise on other ways to check if they indeed match It is weird that mail sometimes get resolved well, but other days just become a mamoth task regards,,Steve