E-mail etiquette

[Miss Zippy]

When is it appropriate to end your e-mail to a work associate (I'm thinking of clients or external people you work, rather than actual colleagues) by writing 'Best regards', 'Warm regards' or 'Kind regards' and is there any difference between these terms? Is one deemed more 'affectionate' than the others?

[ravenhair]

Warm regards is rather rarely used; I would certainly use it only to someone I had already met in person several times and even then, it's not the most common of complimetary closes (this is what these are all called, by the way). Far more commonly used are best regards and kind regards; they're exactly the same in terms of register; however, best regards is a little more frequently used in American English and kind regards in British English.

[comloulou]

Best rule of thumb is, if you wouldnt write it in a letter to a work associate, dont use it in an e-mail.