As a French person, two lines of valediction on paper letters is always funny, and yet required. Especially since the form should be adapted depending on whether you show respect for the person or not.

I once wrote both an employee’s resignation and my acceptance for the conditions of it (on his request for both, he’s non-native), and it was awkward to try to find a valediction that doesn’t put him as inferior.

Language is a treasure.

I had no idea that the form was supposed to be adapted, based on the nature of the relationship.

You can have a fairly good command of a foreign language, but still fail at communicating. You also need to understand cultural conventions and customs, and for that there's no substitute for living there.

I've never written a formal letter in French. I don't know why they sent me to school at all, really.

/me went to a French school, in France, for two years. When I was 4. I know French nursery rhymes.

> "Veuillez agréer, Monsieur, l'expression de mes sentiments les plus agréeables"

That would actually be somewhat familiar for a formal letter. You probably wouldn’t use "les plus agréable" here but rather "respectueux" or "les meilleurs". People just copy and paste them from the internet nowadays when they need to use one.

Thank you for correcting me; I was taught this stuff 40 years ago, and memory is unreliable.

I didn't know that actual French people had to google to find the right terminology for a formal sign-off; that just adds to the hilarity.