There could be a few reasons of why I will not reply, but it is best to note the most likely reasons. In all instances, if you are a scam, or SPAM, I will not reply. If you are hostile or vulgar, I will not reply. If you don’t leave a message, I can not reply.
For email, if you only write one or two sentences, I will not reply. If you are not going to put effort in writing, I am not going to entertain you by replying. It will be good to at least write one paragraph. If you are writing an email for the first time, and need recommendations on writing a good intro, consider thinking of things you would want to know about me, and make that the basis of your email. In other words, if you want to know what kind of music I like, then consider telling me of your musical interests.
For Messaging or SMS, if all you going to do is write OK, or Yeah, then I will assume you lost interest in the message, and will lose interest in trying to keep the conversation going. If you wish to reach out to me via SMS, you can send a message to my [Cellular] Number. This is the most direct option in reaching out to me.
As for telephone calls, any of my publicized numbers should work. However, if my phone is in DND more, then you would go to voicemail. If you don’t leave a valid message, I can not return your call.