Which style of address in business correspondence or when communicating with colleagues do you prefer: using 'you' or 'thou'?

In business correspondence and when communicating with colleagues, it is preferable to use the polite form of address "you". This maintains a professional tone, respect, and formality, especially if you are not closely acquainted with the interlocutor or work in a large company with corporate standards. In informal settings or in teams with a friendly atmosphere, it is permissible to use "you" (informal), but it is better to consider the company's culture and colleagues' preferences.