Manage Spam Settings for OpenSRS Hosted Email

OpenSRS email filters automatically identify and handle spam, and you can fine-tune that handling at the company, domain, and mailbox levels. This article explains how spam settings are inherited, how to mark messages as spam, and how to configure spam detection, headers, tags, folders, and delivery options in both the Control Panel and the Mail Administration Console (MAC).

About spam handling in OpenSRS

Depending on your administrator level, you can configure spam handling at three levels. Settings are applied in order of specificity, with the most specific level taking precedence:

• Company settings. Apply to all users in all domains.
• Domain settings. Apply to all users in a domain and take precedence over company settings.
• User settings. Apply to an individual mailbox and take precedence over domain and company settings.

When you create a new mailbox, its initial settings are inherited from the domain defaults. When you create a new domain, its initial settings are inherited from the company defaults. You can override these inherited values at any level.

You can also choose how aggressively the filtering engine labels mail as spam. Any level other than Normal makes the engine more aggressive, which can catch more spam but may also produce more false positives.

How to mark an email as spam

The most reliable way to report spam is to sign in to webmail and click the Spam button. Marking a message as spam reports its sender, headers, and contents to the email server, which uses this information to filter similar messages in the future. Conversely, marking a message as Not Spam, or moving it from the Spam folder to the Inbox, teaches the filter which messages are safe.

1. Select the message, then mark it as Spam.
2. Click Accept to confirm the message as spam.

About spam headers, tags, and folders

Three settings control how identified spam is delivered to your users:

• Spam Header. Adds specified text to the header of each spam message.
• Spam Tag. Appends a tag to the subject line of each spam message.
• Spam Folder. Selects the folder where spam is delivered.

Keep the following in mind when using these settings:

• Quotas. Items in the system Spam folder do not count against a mailbox quota. Spam delivered to the Inbox or any other folder does count against quota.
• Forwarding tagged messages. The spam tag is not removed automatically when a message is marked as not spam, so users may inadvertently reply to or forward tagged messages.
• Filter improvement. Messages marked as spam or not spam help the server improve detection. Downloading spam to a local client bypasses this learning.
• Automatic cleanup. Messages in the Spam folder older than 30 days are deleted automatically.

Set mailbox-level spam handling

User-level settings take precedence over domain and company settings. You can also reject all messages marked as spam at this level.

In the Control Panel

1. In the Email section of the Control Panel, navigate to the user you want to modify and click the user name. The User Settings tab opens.
2. In the Spam Filtering section, click Edit.
3. In the Safe Senders area, click the plus sign (+) and enter a sender address whose email is always accepted without filtering. Click the plus sign again to add more addresses, one per field.
4. In the Block Senders area, click the plus sign (+) and enter a sender address whose email is never accepted. Add more addresses one per field.
5. Optionally, select Reject Spam to prevent spam messages from being delivered at all.
6. For Filter accounts only, select Override inherited value and choose a Filter Delivery option: Quarantine (do not deliver spam to the reseller's server) or Passthrough (deliver spam to the reseller's designated mail server).
7. In the Spam Detection Level area, select Override inherited value and choose the filtering aggressiveness. A level other than Normal is more aggressive.
8. In the Spam Header area, select Override inherited value and enter the header text. The value must begin with a capital letter, for example X-Spam: Spam detected.
9. In the Spam Tag area, select Override inherited value and enter the tag to append to the subject line.
10. Click Save.

In the MAC

1. Log in to the Mail Administration Console (MAC) and locate the user you want to edit, then click the user name.
2. In the Spam Settings section, in the Allow box, enter sender addresses whose email is always accepted, one per line.
3. In the Block box, enter sender addresses whose email is never accepted, one per line.
4. Optionally, select Reject Spam to prevent spam from being delivered.
5. For Filter accounts only, choose a Filter Delivery option: Use Domain Setting or passthrough.
6. In the Spam Header field, enter the header text, beginning with a capital letter, for example X-Spam: Spam detected.
7. In the Spam Tag field, enter the tag to append to the subject line.
8. In the Spam Folder field, enter the name of the folder where spam is delivered.
9. From the Spam Level list, choose the filtering aggressiveness.
10. Click Update.

Set domain-level spam handling

Domain-level settings take precedence over company settings and apply to all mailboxes in the domain that have no mailbox-level settings.

In the Control Panel

1. In the Email section of the Control Panel, click the Email Domains tab, then click the domain you want to modify.
2. Click the Settings tab.
3. In the User Inheritance section, click Edit.
4. In the Spam Detection Level area, select Override inherited value and choose the filtering aggressiveness.
5. In the Spam Folder area, select Override inherited value and enter the folder name for spam delivery.
6. In the Spam Header area, select Override inherited value and enter the header text, for example X-Spam: Spam detected.
7. In the Spam Tag area, select Override inherited value and enter the subject-line tag.
8. Click Save.

In the MAC

1. Log in to the MAC and navigate to the domain you want to edit.
2. In the Inheritable for Users section, in the Spam Tag field, enter the subject-line tag.
3. In the Spam Header field, enter the header text for spam messages.
4. In the Spam Folder field, enter the folder name for spam delivery.
5. From the Spam Level list, choose the filtering aggressiveness.
6. Click Update.

Set spam delivery options for Filter accounts

For Filter accounts, the Filter Delivery setting controls whether identified spam is quarantined by the OpenSRS email filters or passed through to your mail server. When set to quarantine, spam is held by the filters and end users view or release it from the OpenSRS Spam Portal. When set to passthrough, spam is identified, tagged, and delivered to your server, where your own filtering can route it to the appropriate folder.

If your system already adds a header to spam messages, enter the same value in the Spam Header field so OpenSRS replicates that behaviour and your existing filtering continues to work.

In the Control Panel

1. In the Email section of the Control Panel, navigate to the user and click the user name. The User Settings tab opens.
2. In the Spam Filtering section, click Edit.
3. In the Filter Delivery area, select Override inherited value and choose Quarantine or Passthrough.
4. Optionally, in the Spam Header area, select Override inherited value and enter the header text, for example X-Spam: Spam detected.
5. Click Save.

In the MAC

1. Log in to the MAC and navigate to the domain you want to modify.
2. In the Inheritable for Users section, choose a Filter Delivery option: blank (use company setting), quarantine, or passthrough.
3. Optionally, in the Spam Header field, enter the header text, beginning with a capital letter.
4. Click Update.

Set company-level spam handling

Company-level settings apply to domains and mailboxes only where no domain-level or mailbox-level settings exist.

In the Control Panel

1. In the Email section of the Control Panel, click Settings.
2. In the Domain and User Inheritance section, click Edit.
3. In the Spam Detection Level area, select Override inherited value and choose the filtering aggressiveness.
4. In the Spam Folder area, select Override inherited value and enter the folder name for spam delivery.
5. In the Spam Header area, select Override inherited value and enter the header text, for example X-Spam: Spam detected.
6. In the Spam Tag area, select Override inherited value and enter the subject-line tag.
7. Click Save.

In the MAC

1. Log in to the MAC.
2. In the navigation pane, click your company name.
3. In the Spam Tag field, enter the subject-line tag.
4. In the Spam Header field, enter the header text for spam messages.
5. In the Spam Folder field, enter the folder name for spam delivery.
6. From the Spam Level list, choose the filtering aggressiveness.
7. Click Update.

Next steps

• Release messages from the quarantine spam filter
• Set the FilterMX host for Filter accounts

Questions? Contact OpenSRS Support.