I am usingExchange 2007 onWindows Server 2003.I am usingSymantecMail Security for Exchange with the Premium Anti-Spam for our spam filter. About a week ago something went wrong with the software and it had to be re-installed. Ever since thene-mails fromseveraladdressesare not being recieved. I've checked the log for the spam filter and none of the e-mails are getting caught in it. There have been no changes to our server or network recently besides replacing our modem, but that was about a month ago and we were able to recieve e-mails from the addresses that aren't working now after that.Any ideas on what can be preventing these e-mails from coming through? Thanks,

Hi,Is it possible to switch off Symantec to exclude it from being the cause of the issue ?Regards,Johan blog: www.johanveldhuis.nl

I've tried that. Messages are still not being recieved.

Hi Andrew, Whats the NDR received in the remote side? Could you paste the complete NDR here? Please also use queue viewer to see if these messages hang in queue. - Elvis

Here is one of the error messages the sender is getting. I am waiting on others to see if they are getting the same message. Your message did not reach some or all of the intended recipients. Subject: FW: StrucureWise, Inc. Sent: 1/15/2009 3:15 PM The following recipient(s) could not be reached: sharon@structurewise.com on 1/17/2009 3:16 PM The e-mail system was unable to deliver the message, but did not report a specific reason. Check the address and try again. If it still fails, contact your system administrator. <at-stl-owa1.armstrongteasdale.com #4.0.0 smtp;451 Remote TLS ERROR - Connection closed by peer (state:SSLv2/v3 read server hello A) (host:mail.structurewise.com.) - psmtp>

Hi,It looks like it's trying to send via TLS. This is not accepted for some reason. Please check the certificates on both servers or disable TLS for this sender domain.Regards,Johan blog: www.johanveldhuis.nl

Our certificate expired last week it looks like. I renewed it and e-mails are starting to come through. It looks like that has solved my problem. Thanks for your help.