By all means

Posted by David FG October 18, 2005In reply to By all means posted by Kathy on October 17, 2005

If someone says, "Thank you." and the other person replies, "By all means." what does "by all means" mean?

It is an odd use of the phrase in my opinion. I would expect it to be used in reply to a request:
'could you open the door for me?' 'By all means'. It means certainly - or that is my experience of it.

DFG