I have been told by a (male) person A to give his regards to a (male) person B. I don't know them too well, but I have met them both semi-privately (person A is a coworker of a friend of mine and we have spent a day hiking; person B is an ex-coworker of mine and we had lunch together every now and then), so there is no need to be too formal. They know each other as (ex-)colleagues as well.
How do I do that?
Here are some thoughts of mine; please comment on their correctness, commonness and level of formality/informality. Please also give suggestions.
"Hello B, ...
- "... best regards from A!"
- "... I am supposed to send A's regards to you!"
- "... hello from A!"
- "... I met A recently and he told me to say hi to you from him!"