iMessage doesn't say "delivered" I have an internet friend, we were chatting using imessage, everything works properly until i try to send a message and then imessage doesn't say delivered neither sending. I tried using my other email address to text him, and it works, it says delivered, i know this is weird so i tried again using my first email, but it still doesn't say delivered. Did my friend blocked me?

*i don't have his number, just his email.
If your friend turned off iMessage or turned off Read Receipts, then you won't get the Read notification.  If they're using a beta of iOS 10, they can turn off Read Receipts for individual contacts.

Also, as you suggested, if the friend decided to block you, you won't see the notifications, either. 

EDIT: As indicated in the comments, you will see the Delivered notification even if Read Receipts has been turned off.  Edited answer to reflect that.