It is best if you write a cover letter tailored to the position of your dream (or the position you are planning to apply for in the near future, an internship for example).
Content of a cover letter (personal data, date, employer’s data, at least 3 paragraphs explaining why you are writing, what you can offer, follow up information, and closing)
For an e-mail no personal/employer data
"Looking for a Similar Assignment? Get Expert Help at an Amazing Discount!"