How to address letter to a company [closed]
Here is how it works if the intended recipient is unknown.
If the gender is unknown, use:
Dear Sir/Madam, Dear Sir or Madam, Dear Madam or Sir; Dear Sirs
If the recipient is male:
Dear Sir
Otherwise,
Dear Madam,
If you want to exclude gender altogether from your letter, then use:
To Whom It May Concern
That said, the important thing is what you write. Nobody is going to care much about what kind of salutation you use.