why wont my imessage work for just one contact

Because that contact does not either have imessage (must have an apple device) or if they do they have it turned off.

Have you iMessages them before? If so have you confirmed with them that they have it turned on now, plus they might just not be in an area with a data connection right now

I have the same problem as SWatson12, and the person I'm texting has an iPhone 4S like me and is in my house - so there isn't a question of coverage area or type of phone.

But iMessage still works with this person if I text via my Mac or iPad.

This has been a problem since last night. At first, when I updated to 10.8.2, it worked great!

I had this same problem for the past 2 years. I can iMessage all my contacts who has an iPhone except for my wife's iPhone 4. I also used to have an iPhone 4 and I recently upgraded to an iPhone 5. I've updated the iOS to 6.1.3 and rebooted my phone but still have the same problem. My wife's iPhone 4 has iMessage switch on and activated so she can also iMessage other contacts except for me. This is driving me crazy, can some help please!

I had a problem with messaging my husband and had to change his name on my contacts. I just did his initials and it worked.

I think the problem was that my gmail, iPhone, separate contact with the same name for his work numbers balled it up. It was frustrating because if he was part of a group message the message wouldn't go through.

I just made him "DV" and it worked!

I changed the contact name to 2 initials but no success.

Thanks for your help mvasich, I really do appreciate it. :)

What i did ! Is erase all of out messages or only the green ones! Then go to "cotancts" search for the contacts you wanna text and then press "send message" on there! But both people have to do the same thing! Or! Do the same thing but send the message to the email.. And then try it later with the actual number :)

i know it´s a year later but i just figure it out.

for all the people that are having problems sending blue bubble messages to other contacts even when they do have imessage active,

just go to messages on your mac and send them a message, it should be blue, and now you will be able to send messages trough your phone with no problem or charges for sms...of course if the bubble is blue.