Scan inbound and outbound SMTP traffic

The example shows how to configure malware scanning for inbound and outbound emails.

Introduction

To configure SMTP scanning, you need to create the following firewall rules:

  • Scan inbound SMTP and SMTPS traffic to the mail server.
  • Scan outbound SMTP, POP, IMAP traffic and their corresponding secure protocols.

Scan inbound SMTP traffic

Specify the firewall rule settings to scan inbound SMTP and SMTPS traffic to an internal mail server.

  1. Go to Rules and policies > Firewall rules. Select IPv4 or IPv6 protocol and select Add firewall rule. Select New firewall rule.
  2. Specify the following settings:

    Name

    Settings

    Source zones

    Any

    Destination zones

    Zone in which the internal mail server is hosted.

    Destination networks

    Select the internal mail server.

    Services

    Select the following:

    SMTP[S], SMTP

    Scan email content

    Select the following:

    Scan SMTP

    Scan SMTPS

    The following image shows an example of how to configure the settings:


    Rule for scanning inbound emails
  3. Click Save.

Scan outbound SMTP traffic

Specify the firewall rule settings to scan outbound SMTP and SMTPS traffic from the mail server.

  1. Go to Rules and policies > Firewall rules. Select IPv4 or IPv6 protocol and select Add firewall rule. Select New firewall rule.
  2. Specify the following settings:

    Name

    Settings

    Source zones

    LAN

    Source networks and devices

    Any

    Destination zones

    WAN

    Destination networks

    Any

    Services

    Select the following:

    SMTP[S], SMTP

    POP3, POP3S

    IMAP3, IMAP3S

    Scan email content

    Select the following:

    Scan SMTP

    Scan SMTPS

    The following image shows an example of how to configure the settings:


    Rule for scanning outbound emails
  3. Click Save.