iMessages sent by me to one friend only go to their MacBook not their iPhone iMessages sent from me to my friends, but not others, only go to their MacBook, not their iPhone. However, my friend receives iMessages from others to both MacBook and iPhone. Is the problem at my end or at the other end?
Check that the address or number you are sending to is listed on your friend's iPhone as a receiving address. Your friend can do this in the Settings app > Messages > Send &amp; Receive > "you can be reached at"