Why can't I send a message to one of my contacts?

[iMore Question]

When I try try to send a message from my iPad to his mobile phone, his name on the "To" line is red. If I tap his
Name it says "[redacted]@aol.com" is not registered with iMessage". How do I or he correct this?

 

[Just_Me_D]

If that person does not have an iPhone then you will not be able to send him an iMessage or SMS message.