Use the filters subject and/or content to filter messages by subject and/or content as specified in your push requests. When you use these filters, the Listener automatically adjusts the filter to match the format received by the carrier. For example, you may want to filter a message with the subject Sync and the content Orders. You do not have to worry that in UDP, this would appear as [Sync]Orders, and on one email to SMS conversion service, it would be Bob@mail.com[Sync]Orders.

Your subject cannot contain the closing character that is used to enclose the subject. In the previous example, UDP encloses the subject Sync in square brackets. This means that you cannot use a closing square bracket in subjects that might be received over UDP. For SMTP messages, your carrier determines the character used to enclose the subject. This might be one of ), ], }, >, ' or ".

For SMS messages, the Listener trims leading and trailing spaces, as well as leading and trailing tilde (~) characters, from the sender name, subject, and content. Non-printable characters such as the new line character are deleted by the Listener before filtering.