Why can't I send iMessages to one person?

[iMore Question]

Why can't I send iMessages to one person

hi I've got an iPad version 4 wifi only device,I live in the uk and all my friends I have in my contacts are fine with iMessage and FaceTime, apart from my friend who lives in the usa, the number I use to talk to her is meant to be her Apple ID as well,but when I type her name in the find box,it highlights in red and says Apple ID not recognised,have I typed the number in wrong or something,the only time we can communicate is when she signs out and signs in with her email which seems a lot of hassle, helps greatly appreciated

 

[kch50428]

Re: Why can't I send iMessages to one person

She needs to go into her iMessage settings and make sure the address you're using is set up as one she can be reached via iMesage.

 

[Stuart Mcinnis]

Re: Why can't I send iMessages to one person

Ok thanks, but she should of saved it as she has my email that's how she contacted me