If I tell you something to your face and you give a context-appropriate response, you are accountable for what you were told.
If I tell you something and you grunt or do not respond, you did not hear it. We may be escalating this to the above condition if you are a subordinate, a child, or somebody who actually needs to know what was said. Context and circumstances dictate appropriateness of touching you, striking you, putting something in front of your face, or throwing spitballs at you to get your attention.
If I send you an electronic communication and you do not respond somehow, I will not assume you received the communication. If you do respond or show that you have received an electronic communication, you are responsible for having read all of it regardless of whether you actually did.
If you are cursing, the conversation is over when I say it is, including but not limited to the time I stopped listening and started thinking about what I was doing before you interrupted my life – whether or not I continued to keep acting like I was listening.
Cursing back may be acceptable. Start it, deal with it.
If you want me to know something, contact me in a way that gets you a response. I do not and will not be held accountable for not checking my email or smailmail boxes every day. I do not and do not want to know how to check any of my three or four voice mail boxes. Get me to use words related to what you are talking about, directed at you, if you want to be sure I got your message.
Unless I respond, you may assume that I did not get your letter or email, or else I considered it unimportant-enough to neglect to respond.
If I did not look at you and acknowledge you directly, you did not speak. Coincidentally-timed grunts and things you think you heard me say are to be understood as non-responsive to whatever you were talking about.
I have 5 phone numbers that can be used to reach me. If you know one of them, use it and speak to me directly. I have a regular work and church schedule. Show up in person. Otherwise you have less than 100% surety of knowing I hear you.
We do what is important to us, and this includes remembering. If you REALLY want to make sure I got it, make sure I got it twice. Twice is reminding, and may increase the likelihood of correct remembering. Four times is nagging and you start to be ignored past that point.