[pavlov]

Some pointless pedantry: There is no singular title "Messr", because "Messrs" as the plural of "Mr" comes from the French "Messieurs". The French singular is "Monsieur", which is abbreviated as simply "M".

[jpdoctor]

Pointless pedantry continued: "Messr is now a derogatory term for people who resonate arrogance or give the impression that they are conceited."

http://www.urbandictionary.com/define.php?term=messr

[tripa]

Note that the French language officially shortens "messieurs" as "MM."

[demallien]

It's more often Mr, even in French these days...

[gregschlom]

But it's still wrong (in French).

[Miky]

Could you more clearly define what you mean by “wrong,” please?

[gregschlom]

Writing "Mr." in French is incorrect. The correct form is "M."

"Mr." is English for Mister "M." is French for Monsieur.

I've seen this mistake made even in letters from banks and mobile phone companies. I cringe every time I see it.

[Miky]

I was just trying to say that if using “Mr.” is becoming the norm in French, then it is becoming correct. I don't know if this is actually the case.