When you meet someone new and make plans to follow up at a later date, one of the questions you should ask is "What is the best way to contact you?"
There are some people who prefer to be contacted by email, as it allows them to respond at a time convenient to them, their time uninterrupted by telephone calls.
There are those who prefer to be contacted by phone; they prefer the directness of a live conversation and find the back and forth exchange of electronic messages to be frustrating.
And there are those who like to be contacted only by text. The drawback to this is not everyone knows how to or has the capability to text from their phone. Furthermore, there is a misconception among many that sending a text will result in an immediate response, which is not always possible.
Finally, there are those who are open to any means of contact. If this is you, wonderful -- you are providing the other person with options. If this is not you, then definitely speak up and state your preference; you will be making things easier on both of you.
The key thing to keep in mind when telling someone how you wish to be contacted? Make sure it is a method to which you will respond, ideally in a timely manner. So often I hear from people who tell me they have emailed or left messages for someone and not heard back.
Not only is it frustrating, but it says a lot about the other person's credibility.