Any communication with a potential customer must endeavour to answer the reader’s unheard questions. Your email is unexpected. They are not lying around thinking about your brand. And your email or other communication has just shown up.
So look at it from their perspective – here are the questions they are asking:
1. Who is it from?
2. Is it really for me?
3. Have they spelt my name right?
4. Can I believe what they say?
5. Where did they get my name from?
6. What do they want me to do?
7. Why should I do it?
In a face-to-face situation, a sales person can answer all these questions. Here your online communication must do the same to put the reader at ease.