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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/S, POP/S, and IMAP/S traffic.

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 protocol IPv4 or IPv6 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:

    Select SMTP and SMTPS scanning

  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.
  2. Select the protocol IPv4 or IPv6 and select Add firewall rule.
  3. Select New firewall rule.
  4. 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:

    Select email scan settings

  5. Click Save.

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