In a formal letter addressed to one or more unknown recipients, "Dear Sir or Madam" is the customary salutation. As a German native speaker, who is used to "Sehr geehrte Damen und Herren", writing "Sir" before "Madam" sounds impolite to my ear and I feel the urge to change the order. I know that I must never directly carry over conventional expressions from one language to another, but it makes me wonder:
Are there any differences between "Dear Sir or Madam" and "Dear Madam or Sir"? In particular, would the latter sound more polite or rather come across as outlandish?