The problem with "this is" is that you're referring to oneself in the third human being. Good for introductions of some other person, although not on your own. Say "I'm Joe Doe" or "You might have reached Joe Doe" or even just "Joe Doe". We have been over complicating something https://cashmalgy.tinyblogging.com/5-tips-about-case-study-solution-support-you-can-use-today-82224331