how to write the first E-mail to your customer?

[Goodluck1102]

Everyday, i sent lots of E-mail to some potential customers which i found from internet..but seldom received their reply..

I guess there should some wrong in my business letter or something else..so how do your guys write the first E-mail to your customer?

Also i received some enquiry, but when i sent them the quotation as their request, no answer again..Could u pls kindly tell me: how to reply to customer when they enquiry first time?

Tks for your suggestion in advance.