Barracuda Email Security Service

Step 3: Configure Scanning of Outbound Mail

The Barracuda Email Security Service may be configured to scan outgoing mail simultaneously with scanning inbound mail. To enable spam and virus scanning of outbound mail, follow the steps below.

In this article:

Add Valid Sender IP Address Ranges

From the OUTBOUND SETTINGS > Sender IP Address Ranges page:

  1. Add and verify domains for outbound mail by following the steps in Step 2: Initial Setup of the Service.
  2. Click the Add button. Enter the IP Address and Domain Name (logging domain) and an optional Comment, and then click Add. Note that each mail server must contain a reverse DNS PTR record.

Each IP address from which you want to allow outgoing mail through the Barracuda Email Security Service must be listed on this page. The Logging Domain is the domain name that will appear in the Message Log as the sending domain for the associated IP address.

Important: To assure recipients of outbound mail from your Barracuda Email Security Service that Barracuda Networks is the authorized sending mail service, check your domain's SPF record. Sender Policy Framework (SPF) is an open standard specifying a method to prevent sender address forgery. See Sender Authentication for more information about SPF. If you already have an SPF record set up for your domain, edit the existing record and add the following to the INCLUDE line for each of your domains sending outbound mail:

If you don’t already have an SPF record set up for your domain, you can create a TXT record with the value of

        v=spf1 ~all

This creates a SOFTFAIL Sender Policy Record for your domain.

Configure Your Mail Server or Smart Host

To relay outbound mail through the Barracuda Email Security Service, in your mail server or Smart host, specify the hostname value from the Outbound Hostname field on the DOMAINS > Domain Manager page for each domain from which you'll be relaying outbound mail.

Verify That Mail is Flowing

Check the DASHBOARD and MESSAGE LOG pages to make sure that inbound and outbound messages are being logged for the selected domain. The Message Log page provides rich searching using a set of keywords with your search words or phrases. See The Message Log for more information on filtering messages.

What Outbound Mail Scanning Includes

  • Spam Scanning with Block or Quarantine actions
  • Virus Scanning  
  • IP Address Filtering
  • Sender Domain, Username or Email Address Filtering
  • Recipient Email Address Filtering
  • Content Filtering (Subject, Header and Body) with Block, Allow, Encrypt or Quarantine actions
  • Attachment Filtering
  • Intent Analysis

See also Outbound Quarantine.

The following scanning tools are not applied to outbound mail:

  • IP Reputation, a sender authentication mechanism
  • SPF (Sender Policy Framework), a sender authentication mechanism
  • Whitelist/blocklist
All messages going through the Barracuda Email Security Service are subject to a size limit of 300MB. This includes all headers, body and attached content.

Encryption of Outbound Mail

To prevent data leakage and ensure compliance with financial, health care and other federally regulated agency information policies, you can require all email sent from any or all domains configured in your Barracuda Email Security Service to be encrypted. Create policies for encryption of outbound mail in the OUTBOUND > Content Policies page at the domain level. See How to Use DLP and Encryption of Outbound Mail for more information.

Transmission of inbound and outbound email can be required over a TLS channel as well - see Secured Message Transmission for details.

Outbound Message Footer

The Barracuda Email Security Service can append a custom text and/or html footer to each outbound message, configurable at the global level on the OUTBOUND SETTINGS > Tagline/Footer page.

Continue with Step 4: Tune and Monitor the Default Spam and Virus Settings.

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Still need help?

If you have a technical issue with the product, please contact Barracuda Networks Technical Support.