No response to Health Check with SMTP Prevent.
SMTP Prevent will drop an incoming connection if the downstream MTA does not respond. Therefore, If SMTP Prevent is being used in reflect mode, the system generating an SMTP health check must also act as an SMTP server on the port specified by RequestProcessor.MTAResubmitPort or the SMTP health check will fail.
Reflecting Mode Health Check Example:
HealthCheck | Symantec DLP Email Prevent | MTA |
Create Connection -> | ||
Create Connection -> | ||
<- 220 Banner | ||
<- 220 Banner (from MTA) | ||
HELO -> | ||
HELO -> | ||
<- 250-EHLO Response Line 1 | ||
<- 250-EHLO Response Line 2 | ||
<- 250-EHLO Response Line 3 | ||
<- 250-EHLO Response Line 4 | ||
<- 250-EHLO Response Last Line | ||
<- 250-EHLO Response Line 1 (from MTA if not filtered by Prevent) | ||
<- 250-EHLO Response Line 2 (from MTA if not filtered by Prevent) | ||
<- 250-EHLO Response Line 3 (from MTA if not filtered by Prevent) | ||
<- 250-EHLO Response Line 4 (from MTA if not filtered by Prevent) | ||
<- 250-EHLO Response Last Line (from MTA if not filtered by Prevent) | ||
Quit -> | ||
Quit -> | ||
<- 221 Connection Close Message | ||
<- Connection Close | ||
<- 221 Connection Close Message | ||
<- Connection Close |
See also: article 159446 : How do I set up an SMTP Prevent Connectivity Check on windows?