Each person is different and 'refreshing' in their own way...
What you type, how you type, the feeling emitted, the overall meaning... I take them into consideration. I won't neglect something like a brief 'hello, how are you?' as something insignificant, mundane, repetitious, or bothersome.
No matter how brief or how long... a person still wrote it... Took time to write something that has emotion, heart, or thought...
Therefore, I thank them for leaving these messages despite my slow response.