I have a new install of exchange 2007. It seems that some emails from external senders come through very quickly (almost instantly) and some emails either never come through or take up to 12 hours to arrive. No NDR's are sent. I have configured DNS properly and DNSReport.com checks out fine. The server is running as a hub transport server because we are a small company and do not have budget for 2 exchange servers. Anti-spam blocking is disabled for now in order to troubleshoot. I have 2 receive connectors, one for port 587 and one for port 25. The server has 2 IP addresses, one internal and one external. I am also using Hyper-V server to host an external, non-member web server, which works fine. The exchange server is also the domain controller. Both receive connectors are allowing anonymous user permissions (not open relay though). Server specs: AMD Athlon X2 2.1 GHz 5GB RAM (768 MB Dedicated to virtual web server) 250 GB RAID 1 Mirror Dual Intel NIC

Hi DataMasterUSA You need to discover where the delay is. Message trackingwill do that for you. http://www.amset.info/exchange/message-tracking.aspThanks

If emails arrive after 12 hours that means they are sitting somewhere in the mean time. Depending on where that is, the cause varies. If a sending server tries a few times to send mail to your domain and is unsuccessful it will wait for a period of time(s) and then resubmit. So this means the messages are sitting on the sending server waiting. If this is the case you need to enable protocol logging and figure out why the sending server is unable to make the initial connection. A delay this long should however trigger a delayed status notification on the sender side so if youre not seeing one of those, its probably entered your environment successfully. If you examine the logs and discover the line: 250 Queued mail for delivery this means your server HAS accepted it and it is either in one of the queues OR stuck in your antivirus application (do you have one?). If this is the case, open queue viewer and report back what queue its stuck in. Mike Crowley A+, Network+, Security+, MCT, MCSE, MCTS, MCITP: Enterprise Administrator / Messaging Administrator

So I have checked the message routing logs and the connection logs. It looks like the sending domain doesn't even try to connect. The server is also a domain controller and is multi-homed. I can telnet to port 25 and the response is very quick from both internal and external domains. The message routing log does not show any connection attempts. I worked with one sender who said that the emails had left their servers, but I have no indication as to what happened to them. They do not get an NDR and their smtp server's IP address is in my global allow list. Not sure what's going on.

Hi, Do the issue happen only on this domain? How about the other domains? From your description, we could see the mail is not received by your server. So the remote side should get a NDR or the mail is stuck in their queue. Please suggest their admin use the queue viewer to look for more information. The messages hang in which queue and whats the last error for that queue. I understand you could telnet your port 25, but we need to make sure if the remote side can do this. Please suggest them to do a telnet and try to send a email, see what happen. Thanks, Elvis

Hi,How things are going? If any update, please post here. Thanks,Elvis