Juan:'I need to reply to this email and I'm a little confused about how to start my email. Can you help?'
Peter:'Well, first of all you need to write that you're replying to their email. So normally you write Further to your email. Or you could use With reference to your email. They are basically the same. You can use both if you're responding to an telephone conversation or a question somebody asked you in a meeting etc... For example, "Further to our telephone conversation...".'
Juan:'But what if it's not replying or responding to anything? What could I use?'
Peter:'Then use I am writing in reference to.'
Juan:'And something for both, which is more informal would be?'
Peter:'For less formal emails (when writing to a work colleage like you for example) I normally start with, I hope everything is ok. Which is polite small talk. And then depending on what the subject or purpose of the email is, I would write, "have you heard anything about...", or "what's happening with..." or "I just thought that I'd let you know that..."'
Juan:'And after that. What would I say if I am going to confirm some information or answer some questions that they asked me in the email? Something formal.'
Peter:'I suppose use I can confirm that, if you're going to write the information in the email. If the information is in a separate file, then I'd say that I have attached the information in following document.'
Juan:'And if I'm confirming or telling them some good or bad news?'
Peter:'For bad news, I would use we regret to inform you that. And for good news we are pleased to inform you that.'
Juan:'And if you're asking for information?'
Peter:'Well, a formal way would be could you please confirm. An informal way to say the same thing, would be simply to say do you know.'