Customers creating regular expressions (Regex) such as when adding Advanced Content Filtering Rules will sometimes need to know which language syntax MailEssentials expects for validating the regular expressions.
This information can be found under the GFI MailEssentials > General Settings > About node and selecting the 3rd Party Licenses tab which lists all third-party components used by GFI MailEssentials.
This tab lists the various third-party libraries and versions of those libraries that the system utilizes for various product functionality.
The XRegExp library developer recommends the following tools for regex construction and validation:
Additional Regex tools: