1. I am sure you are surprised to receive my e-mail.
2. I am sure you will surprise to receive my e-mail.
3. I am sure you will be surprised to receive my e-mail. –
In sentences 1 & 3 “surprised” is used as an adjective meaning “feeling surprise”.
Sentence 1 is in the present tense. It can be used, for example, in an e-mail you are sending to someone whom you think does not expect an e-mail from you. “I am sure” is written in the present tense, because what you feel sure of is felt at the moment of writing. Although the person you wrote to may receive the e-mail some time after you wrote it, his reaction at the moment of reading it should also be expressed in the present tense.
The first clause in sentence 3 is in the present tense and the second clause in the future tense. Although the statement may sound correct, it is illogical. If you tell someone he will be surprised to receive something from you, he won’t be surprised when he receives it, because you’ve already told him.
It’s different if, for example, you were to phone him before you write the e-mail and say
“I am sure you will be surprised by the content of my e-mail.”
In this case, you are only telling him he will get an e-mail from you, but not what you are going to write in it, which you’re sure will surprise him.
Sentence 2 is ungrammatical. There, “surprise” is used as a verb, but without an object. “Surprise” is always a transitive verb which requires an object. You could write, for example, “I am sure that getting an e-mail from me will surprise her.”, where “her” is the object of the verb “surprise”.