Reason for writing an email

Formal

• I am writing to make a reservation for Christmas lunch. 
• I am writing to apply for the position of account manager.
• Could you please confirm my booking at your earliest convenience? My booking code is J3Y4K5.
• I am writing to ask for further information about the conference taking place at your hotel next weekend.
• I am writing with regard to the sale of a house in Prato and the olive trees.
• I am writing in response to the complaint you made on February 14th.
• Thank you for your e-mail on February 15th regarding the terrible Valentines Day Dinner at your restaurant.
• I am writing you about a problem concerning the conference in Brussels.
• With reference to our telephone conversation on Friday, I would like to let you know that we selected another candidate for the position of account manager.