Quoted from FrederikFrost:I use "best regards" or even "regards" everytime I write to people.. Be it here on pinside, over e-mail or anything else. As an European guy without having english as my native language I don't really know what to use other than regards or best regards.. Sincerely seems too personal, doesn't it? I don't know, but I think it's bad mannered to jump the gun simply due to a formality like that O.o
There is nothing wrong with using "regards" or "best regards", I don't know what those guys are going on about. It is a common practice in formal letter writing.
Best regards,
PEN