How do you usually treat a person that look at you suspiciously?.. Probably, distrustful.
It's so important to realize that the inner state of your interlocutor affects your attitude and perception about him. This works same for him: your inner state effects his perception about you and your message! Our inner world is usually affected by emotions we experience at the moment of communication.
Let see how does it work.
Imagine a situation. You established an appointment with somebody. This somebody is late for 10 minutes. Now imagine 2 scenarios:
1) This somebody is a lovely person you care a lot and like unconditionally. What would you say to him or her when she would come?
"What happened, sweetie?"
"Oh, so glad you arrived, I was really worrying what happened"
"My dear, I am so happy to see you, did you arrived safely?"
2) Now imagine that this somebody is a person that always irritate you by unsuitable stupid comments and intrusive questions. You were pretty much forced to come to this meeting. What would you feel or say when the person has arrived?
"Oh, God, finally you arrived, I was ready to leave the place"
"Why it took for you so long? Don't you have a phone to call and announce me that you will be later"
"What an frivolous attitude!"
So, these 2 simple situations demonstrate us how much our attitudes effect our emotions and could make a huge difference in communication. It could be super supportive and positive. Or it could kill any successful communication!