IPS tab

Automatically detect and inspect the protocol

If this protocol is enabled, the inspection function will automatically apply to discover corresponding traffic that filter rules allow.

SMTP protocol extensions

Filter the CHUNKING extension	Allows filtering data transferred from one e-mail address to another. EXAMPLE Attachments in e-mails.
Filter Microsoft Exchange Server extensions	Allows filtering additional commands from the Microsoft Exchange Server.
Filter request to change ATRN and ETRN connection direction	Makes it possible to filter data contained in the request to change connection direction, from the client to the server, or from the server to the client. During an SMTP communication, the use of ATRN and ETRN commands allows exchanging the client/server roles.

Imposing a maximum size for elements (in bytes) allows countering buffer overflow attacks.

Message header	Maximum number of characters that an e-mail header can contain (e-mail address of the sender, date, type of encoding used, etc.). The values allowed for this field must be between 64 and 4096.
Server response line	Maximum number of characters that the response line from the SMTP server can contain. The values allowed for this field must be between 64 and 4096.
Exchange data (XEXCH50)	Maximum volume of data when transferring files in MBDEF format (Message Database Encoding Format). The values allowed for this field must be between 102400 and 1073741824.
BDAT extension header	Maximum volume of data sent using the BDAT command. The values allowed for this field must be between 102400 and 10485760.
Command line	Maximum volume of data that a command line can contain (excluding the DATA command). The values allowed for this field must be between 64 and 4096.

Disable intrusion prevention	When this option is selected, the scan of the SMTP protocol will be disabled and traffic will be authorized if the filter policy allows it
Log every SMTP query	Enables or disables the logging of SMTP requests.