Understanding custom filtering

FPE enables you to create and manage five types of filters to help manage your email. The filtering options in FPE allow you to create highly configurable lists of criteria (such as a phrase in the message body or the sender email address) that you can use to take action on email messages. These filters are applied to each message during the scan process after spam and malware filtering.

You can create multiple filter lists for each of the five filter types. You can enable and disable the filter lists on an individual list level for each scan where the filter type is supported. For example, if you create a subject-line filter list, you can enable it for the transport, realtime, and on-demand scans, and disable it for the scheduled scan.

Exchange Server also has filtering options available that will continue to filter messages, even when FPE is installed on your Edge Transport and Hub Transport servers. These options are automatically enabled on the Edge Transport server role and can be manually enabled on Hub Transport server role. Exchange filtering and FPE filtering functionalities are similar, yet there are several notable differences. For example, FPE offers case-sensitive keyword filtering and can filter by file type. For more information on using Exchange filtering with FPE filtering, see Using Exchange filtering.

You can use a combination of Exchange and FPE filtering options to maximize filtering functionality.

Allowed senders

Allowed senders filter lists enable you to maintain a list of safe email addresses and domains that bypass either the file, content (subject line and sender-domain), or keyword filters, or a combination of the three. This filter is available only for the Edge Transport and Hub Transport scan. For more information about allowed senders filter lists, see Creating an allowed senders filter list.

File filtering

File filtering enables you to filter email attachments by file type, name, extension and size. File filter lists are available for all scan jobs. To learn more about file filters, see Creating a file filter list.

Keyword filtering

Keyword filtering helps you identify unwanted mail by analyzing the content of message bodies for instances of words, phrases, and sentences that you configure. Keyword filter lists are available only for transport scanning. For more information about keyword filter lists, see Creating a keyword filter list.

Sender-domain filtering

Sender-domain filtering enables you to filter messages by specified senders and domains. Sender-domain filter lists are available for all four scan jobs. For more information on sender-domain filtering, see Creating a sender-domain filter list.

Subject line filtering

Subject line filtering takes action on messages, based on words and phrases found in the subject line. Subject line filter lists are available for all four scan jobs. For more information on subject line filtering, see Creating a subject line filter list.