You got a proper introduction, you checked your grammar, you checked your spelling, but that may not be enough to get you reply from your new friends. You may need to finish your message strong and smooth.
I recommend that you finish your messages with interesting questions which trigger next conversations. With such messages, your new friends will feel much more comfortable writing you back. If your message end with a statement or too general question, your new friends will have a trouble writing you back. (he/she will not know what to write back to you, and it's boring.) And what's more, it's better if you can make your questions as specific as possible. Instead of "what do you think about coffee", say "do you like espresso more than regular blend coffee?"
After all, it's all about balance. Ask questions but don't ask too much questions. Write about you, but don't write too much about you. Keep it short, but don't make it too short. Write friendly, but don't be too friendly.
Good luck, and enjoy meeting new friends at Antangle.com