General salutations are appropriate no matter who receives the letter. Open with "To whom it may concern:" if you are not writing the letter with a specific person in mind. For instance, you might use this salutation for a letter that will be sent to a number of different people. “Dear Sir,” “Dear Madam,” or “Dear Sir or Madam” are all perfectly acceptable salutations for a formal letter. This is slightly more personal than a general salutation. For business letters directed to a person in a certain profession, consider using the recipient's job title in the salutation. This shows respect for their position. For instance, you might begin with “Dear Editor:" or “Dear Human Resources Director:”
اعتمد على التحيات العامة في حالة عدم التأكد من هوية مُستلم الخطاب. استعمل لقب "السيد" أو "السيدة" في حالة عدم معرفتك لاسم من تراسله. استعمل اللقب الوظيفي للمُرسل إليه في التحية إذا كُنت على دراية به.