Attachment Filters
All outbound messages, including those from exempt senders, go through attachment filtering. On the Outbound Settings > Content Policies page, you can select to filter text matching the entered pattern based on File Name or MIME type, and select whether to Block, Ignore, or Quarantine outbound messages. Additionally, you can select to Block, Ignore, or Quarantine attached archive files that require a password to unpack.
Password Protected Archive Filtering
For outbound mail, you can select to block, quarantine, or ignore messages containing archive file attachments. Selecting Ignore means that the service does not look for, or act on, emails with attachments that require a password to unpack.
Password Protected Microsoft Documents
For outbound mail, you can select to block, quarantine, or ignore messages containing password protected Microsoft documents. Selecting Ignore means that the service does not look for, or act on, emails that contain password protected Microsoft documents.
Password Protected PDF Documents
For outbound mail, you can select to block, quarantine, or ignore messages containing password protected PDF documents. Selecting Ignore means that the service does not look for, or act on, emails that contain password protected PDF documents.
Message Content Filters
Customize content filtering based on any combination of subject, headers, body, attachments, sender, or recipient, and apply to outbound mail. See the Outbound Settings > Content Policies page for settings. Filter actions for outbound mail include Block, Allow, Quarantine, Encrypt, and Do not encrypt.
Messages that meet the Quarantine criteria are sent to the Outbound Quarantine for the administrator to evaluate. Messages can then be viewed, delivered, rejected, deleted, or exported from the Overview > Outbound Quarantine page.
Enter filter patterns and select to Block, Allow, Quarantine, Encrypt, or Do not encrypt for Subject, Headers, Body, Attachments, Sender, or Recipient. Note that Header filters are applied to both the header name and content of any header, while the Subject filters only scan the contents of the Subject header. Use regular expressions as well as the following special characters:
. [ ] \ * ? $ ( ) | ^ @
See Regular Expressions for text patterns you can use for advanced filtering.
When using the above special characters, you must escape each character with a backslash ("\").
Attachment Content Filtering is limited to text type files such as most MS Office files, html, pdf files, and other document files.
Predefined Filters
Select a predefined data leakage patterns (specific to the United States) for Subject, Headers, Body, or Attachments. Select whether to Block, Quarantine, or Encrypt outbound messages based on the filter.
Order of Precedence for Attachment Filters, Message Content Filters, and Predefined Filters
The Attachment Filters, Message Content Filters, and Predefined Filters support the following actions, in the following order of precedence:
Order | Filter | Action |
|---|---|---|
1 | Message Content Filter | Allow |
2 | Message Content Filter | Block |
3 | Predefined Filter | Block |
4 | Attachment Filter | Block |
5 | Attachment Filter | Quarantine |
6 | Message Content Filter | Quarantine |
7 | Predefined Filter | Quarantine |
8 | Message Content Filter | Do not encrypt |
9 | Message Content Filter | Encrypt |
10 | Predefined Filter | Encrypt |
Predefined Filter Exceptions
Add exemptions to predefined HIPAA or Privacy content filters to prevent outbound emails that include phone number or street address items from being blocked, quarantined, or encrypted.
Image Analysis
Image analysis techniques protect against new image variants. Image analysis is automatically configured in Email Gateway Defense.