Hi all:
We can't recommend mailing your semen for a few reasons.
Apparently there are special transportation guidelines for transporting blood and body fluids and a person could get in trouble for not transporting properly.
Also there could be bacterial growth in the semen in five days. If that happened it would not be a healthy thing for your partner to consume the semen at that point. When there are bacteria present there may be unpleasant odors as well.
Hope that answers your question
HN