About URL types

Types of URLs that URL filtering can scan include:

• Absolute URLs — URL syntax with scheme name (protocol), such as http, https, and ftp. They often only include a domain name. Example: http://www.example.com
• Reference URLs — No scheme name. Example: example.com

URLs in email can also be written in plain text instead of as clickable HTML links. While not technically a URL, the domain name of the sender can also be inspected.

By default, FortiMail scans for absolute URLs only. If you need to improve the spam catch rate or reduce false positives, you can change this. Use the CLI command:

config antispam settings

set url-checking {aggressive | extreme | strict}

end

For details, see the FortiMail CLI Reference.