Hey I am looking for a solution to be warned when sending a message and there is certain keyword included in the text. Or for example, if a cetain keyword like “attachment” is included but there is not attachment added to the message.
You don’t specify if this is using the web interface or an email client.
As noted by Julian, many email clients will automatically do this.
For the web interface, the RT correspondence form will already remind you if the word attach (and similar) is present, but nothing is attached. This feature was added in RT 4.4.0. - RT 4.4.0 Release Notes - RT: Request Tracker - Best Practical .