Don't worry about the literal meaning of the phrase - it's simply a formula that you put at the end of emails, notes and letters. It's a polite and friendly way to sign off a correspondence.

Best Regards be similar to write have a nice day.

It means: respect, consideration, esteem. I agree on what Su.Ki said before, a polite way to sign off a correspondence.

Sunny, best regards means wish you well, just like "kind regards", "warm regards", "regards", "cheers", "sincerely" etc. If you think about the literal meaning, you will go crazy. The bottom line is, these are used to end an email/mail politely.

"Regards" means, literally, "thoughts." In this case, it is understood to mean "thoughts about you."±± "Best regards" means, literally, "with kind thoughts about you." As others have noted, it is a pure formula or convention. It doesn't actually communicate anything at all but politeness and etiquette. I would end a formal business letter with "Very sincerely yours;" a social letter to someone who was not a close friend with "Best regards;" and a social letter to close friends or family with "Love."