meaning

[DonnaLS]

What does this mean when a person says to me,
Thank you, your support knows no boundaries?

[Anglika]

Your support knows no bounds = has no end to it.

"Bounds/boundaries" define a space, like a field or a country.

[BobK]

What does this mean when a person says to me,
Thank you, your support knows no boundaries?

As Anglika says, 'knows no bounds' is the more common form; but you have the meaning now. So the person who says this to you can mean one of two things:

Either 'you have always been a very supportive person', or 'I know I can rely on you to be supportive whatever the circumstances' (probably a mixture of the two).

b