Giving good news
Enclosing something
Offering assistance
Referring to future contact
Giving bad news
Making a request
Making reference
Giving the reason for writing
I am afraid that ...
I am writing to ...
I am pleased to ...
I enclose ...
If you require any further information, please do not hesitate to contact us.
I look forward to receiving your reply.
With reference to your letter of ...
We would be grateful if you could ...