The letter must be written on behalf of the organization, while the author of the message can be any employee of the company who is a specialist in exactly the area in which the request is sent. The main condition: he is obliged to act exclusively in the interests of the employer.
If the letter is not compiled by the leader himself, but by one of the subordinates, it must be agreed upon with the higher authorities (to avoid further disputes, conflicts, and misunderstandings).
Letters marked “personally in hand” are drawn up, as a rule, directly by the director of the organization addressed to the head of the addressee of a similar level. In this case, they should not be opened by anyone other than the recipient himself.
A letter of inquiry can be addressed to a specific person, for example, a director of a partner company, a manager of a division, a specialist in an industry, etc. In this case, when contacting, you need to use the epithet “Dear” and the name and patronymic of the employee.
This form of appeal significantly increases the chances that the request will be considered shortly and a response will also be promptly drawn up (moreover, on behalf of the person to whom the message was addressed).
The request can also be intended for a group of persons without an exact indication of the employee (for example, “to the legal department”, “to the accounting department”, etc.).
In this case, the response to the request can be made on behalf of any employee of the department to which the letter was received.