Sending a busy manager a long email represents a problem in which area of the communication process? message decoder, sender, message encoder, message channel

Message encoding includes selecting and organizing a message. Messade decoding includes interpreting a message. Sender is the person who sends the message (the e-mail). Channel is the way in which the sender and the receiver of the message communicate (note, conversation, e-mail). In our case it is e-mail. 
Sending a busy manager a long email represents a problem in the message decoder as an area of the communication process, because the manager is too busy and may be not able to read the message.

Begin with the first image and just follow them in order.