When Deep Discovery Email
Inspector blocks an email message based on
Sender Filtering settings, Deep Discovery Email
Inspector sends
the following SMTP error codes to the upstream MTA.
 |
NoteMake sure that the upstream MTA can take the necessary pre-configured actions upon
receiving
these error codes. For example, creating an event log or sending notifications to
senders.
|
|
Blocking Feature
|
SMTP Error Code
|
Message
|
|
Sender Filtering/Authentication settings (DHA Protection, Bounce Attack
Protection, SMTP Traffic Throttling, SPF, DKIM, DMARC)
|
421
|
Block temporarily (Sender Filtering/Authentication)
|
|
521
|
Block permanently (Sender Filtering/Authentication)
|
|
|
Email Reputation Service
|
450
|
Temporary denial of connection (450) for Zombie matches (ERS)
|
|
550
|
Permanent denial of connection (550) for RBL+ matches (ERS)
|