Para aqueles que estão tentando descobrir se há problemas com seu exchange, recomendo ua ferramenta. o SmtpDiag www.microsoft.com/downloads/details.aspx
basta usar via linha de comando o smtpdiag.exe remetente destinatario
Com isso, podemos identificar problemas de saida de email.
Searching for Exchange external DNS settings.
Computer name is NRV.
VSI 1 has the following external DNS servers:
There are no external DNS servers configured.
Checking SOA for nrv.com.br.
Checking external DNS servers.
Checking internal DNS servers.
SOA serial number match: Passed.
Checking local domain records.
Checking MX records using TCP: sacred.com.br.
Checking MX records using UDP: sacred.com.br.
Both TCP and UDP queries succeeded. Local DNS test passed.
Checking remote domain records.
Checking MX records using TCP: nrv.com.br.
Checking MX records using UDP: nrv.com.br.
Both TCP and UDP queries succeeded. Remote DNS test passed.
Checking MX servers listed for alexandre@nrv.com.br.
Connecting to aspmx.l.google.com [74.125.45.27] on port 25.
Successfully connected to aspmx.l.google.com.
Connecting to alt1.aspmx.l.google.com [209.85.229.27] on port 25.
Successfully connected to alt1.aspmx.l.google.com.
Connecting to alt2.aspmx.l.google.com [72.14.221.27] on port 25.
Successfully connected to alt2.aspmx.l.google.com.
D:\smtp\SmtpDiag>