IPhone won't send iMessages?

Recently we had an electrical probably at my house so for a few minutes while I was texting iPhone users, I had to send some texts via SMS to get them to go through. Afterwards though after everything was all fixed, my phone still will not send iMessages to this one number, that, yes, I'm 100% sure is an iPhone user. My phone is sending iMessages perfectly fine to all of my other contacts with iPhones, it's just this one number that I had to send SMS texts once. I have tried everything from switching the contact phone number to and iPhone number and back several times, I've turned and turned off the iMessage settings in messages, I've reset my phone while doing all these things, I've tried deleting the messages and starting new messages, and I've tried completely deleting the contact and just typing in the number. None of these things have worked! I'm so frustrated and please any suggestions will help.

Check the reception

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