I have a problem here. I have One Exchange organization with 1 Exch2007 srv and 2 Exch2010 srv's. From one day to another, email delivery is taking hours to be sent to external domains. Users are able to send/receive emails to the same internal domain, and to receive emails from external domains. But not to sent. I have a lot of Application Event Logs with the errors: This is an SMTP protocol error log for virtual server ID 1, connection #26. The remote host "192.168.1.2", responded to the SMTP command "rcpt" with "554 5.7.1 <postmaster@mail.lacostena.com.mx>: Relay access denied ". The full command sent was "RCPT TO:<postmaster@mail.lacostena.com.mx> ". This will probably cause the connection to fail. I have already checked the box "Allow all computers which successfully authenticate to relay regardless of the list above " on every SMTP Virtual server for the 3 servers, and set the Anonymous aditionally. But i'm still in the same status. Can anybody give me some direction on this issue. I appreciate in advance.

Hi, Are you sending e-mails to the internet using a smarthost with IP address 192.168.1.2?? If yes you need to make sure that this smarthost allowa the exchange servers to relay through it. Leif

I have a big problem here, exchange servers are not allowing to send emails. Can i reach you offline? mi email fsferrus@hotmail.com thanks Fernando-

Hi, You didn't answer my question :-) The issue sounds like aproblem with a smart-host - do you have an antivirus/ antispam device that is used as the smart-host then the problem is most likely in this box. Leif

Did you find the problem? Leif

In addition, I recommended you refer to the following article to troubleshoot the issue. http://support.microsoft.com/kb/895853/en-us Thanks. Novak