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Barracuda Email Security Service

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Barracuda Email Security Service IP Ranges

See Active Directory Authentication for a list of IP addresses that must be allowed for uninterrupted access to LDAP from the Barracuda Cloud.


Barracuda Email Security Service IP address ranges based on the region you selected for your Barracuda Email Security Service:

Important – Note that the IP addresses below are in CIDR notation and express a range of IP addresses. Be sure to use the entire range in your configurations, including the first and last IPs in the range.

Customers Using the Following Instances of the Barracuda Email Security Service Instance






United Kingdom


United States

US: and

Ensure Connectivity and Redundancy

Follow these tips to ensure connectivity and redundancy:

  • Open your firewall ports to allow the IP address ranges, based on your Barracuda Email Security Service instance
  • (Optional) Configure your mail server or router to block inbound email not originating from your Barracuda Email Security Service IP address ranges.
  • If you have a Barracuda Web Security Gateway or Barracuda Web Application Firewall: You might need to exempt ess.barracudanetworks.com from filtering.
  • Exempt traffic coming from the Barracuda Email Security IP addresses from any kind of throttle or rate controls.

How to Add the IP Ranges to Office 365

Use the following steps to add the Barracuda IP ranges to your receive connector in Microsoft Office 365:

  1. Log in to the Office 365 admin center, and go to Admin centers > Exchange.
  2. In the left pane, click protection, and click connection filtering at the top of the page.
  3. Click the + symbol, and in the add allowed IP address field, enter the first IP range to allow.

  4. Click OK.

  5. Complete steps 3 and 4 for the remaining IP ranges.
  6. Click Save when you are done adding the Barracuda IP ranges.

Staying in Compliance

The Subscription section in the Overview > Dashboard displays the active users on your account and the total number of user licenses on your account:

  • Purchased – Represents the number of user licenses on your account.
  • Active – Represents the total number of users on your account that the mail server recognizes in the Barracuda Email Security Service in a 30-day period.
Option 1. Purchase Additional User Licenses

Contact Barracuda Networks customer service to purchase additional user licenses.

Option 2. Update Automatically Add Users Setting

When Automatically Add Users is set to Yes on the Domains > Domain Settings page, the service automatically creates an account for a user not currently in the User List when the Barracuda Email Security Service receives mail for two days within a seven day period from that user.

  • To avoid invalid user creation, enable recipient verification on your mail server. If you do not enable recipient verification on your mail server and set Automatically Add Users to Yes, the system might create more user accounts than are needed.
  • You can change this value to No.
Option 3. Remove Recipients from the User List

You can remove users that were manually added (not LDAP) on the Users > Users List page.

If you click Bulk Delete you are prompted to remove all users in the list, not just the selected users.

  1. Enter all or part of a user name or email address, and click Search.
  2. Click Delete in the Actions field, and click OK in the Confirmation dialog box.
  3. Complete these steps for each user you want to remove.
Option 4. LDAP Accounts

If you automatically create user accounts for all users in a domain based on your LDAP directory but not all of those users need a user license, you can disable directory services on the domain and manually add only those users that need access through the Users > Users List page, or adjust the user list via LDAP or Active Directory on your mail server.

Manage Support and Partner Access

Manage Barracuda Support and partner access to messages from the Support tab in the Barracuda Email Security Service.

Support Access

Barracuda support access is enabled by default. To disable access, click Disable Support Access. Note that you must enable Support Access to allow Barracuda Support to investigate message content.

Partner Access to Messages

Partner access to messages is enabled by default. To disable access, click Disable Message Body Access. When disabled, partners can continue to manage your accounts but cannot view the content (message body) of emails for these accounts.



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