There is no such thing as an email marketer that knows it all. Many organizations want a jack of all trades (who is an expert); unfortunately, that person does not exist. There are eight types of email marketers out there. A person can be a blend of 2 or even 3 of these, but no one can be an expert at all eight, and If they say they are, they are lying.
Check out this video to learn more about the following types of email marketers: