Hi All, Our customer has setup of Exchange 2007. One serverfor Mailbox, Hub and CAS and one server configured as Edge. All at sudden smpt stopped responding. Logs could not help as there is no critical error or warning logs, all are information only. All the configuratioin seems to be fine. we can see que on edge server, but mails could not be delivered to mail box server. when we try to telnet from Edge server to mailbox server, we recieve the errorr.421 4.3.2 Service not available, closing transmission channel.There is no AV installed on mailbox and edge server. but Macafe is running on the LAN.Kindlyhelp me in troubleshooting the issue. Please feel free if further informations or input is required.

Hi,From your post, I understand that the inbound email could not be received by mailbox server. When trying to do telnet, the error message stating"421 4.3.2 Service not available, closing transmission channel" was received.First, I suggest we disable McAfee to test this issue.Additionally, please run get-receiveconnector |fl command in EMS, then post the information on the forum.ThanksAllen

Hi Allen.Thanks for your suggestions. We disabled McAfee, though it was not running on any of the exchange server.During our troubleshooting it was observed that our customer tried to apply service pack, which they could not apply successfully and causing exchange in hang state. and mail flow stoped responding. after sometime Exchange was shutdown (force shutdown) and resulted in corupting the IIS and Hub. Reinstalling both the services, mail flow start working fine.

Hi,I am glad to hear that the issue was resolved due to the services issue.Thank you for your sharing.Allen