His thanks

of his or her own accord; with his or her good will; voluntary.

See also: thank

References in classic literature ?
Collins, and as they walked down the garden he was commissioning her with his best respects to all her family, not forgetting his thanks for the kindness he had received at Longbourn in the winter, and his compliments to Mr.
Thank you, Monseigneur, thank you," said Cornelius, nearly swooning with joy, and staggering on the steps of his carriage; had not the officer supported him, our poor friend would have made his thanks to his Highness prostrate on his knees with his forehead in the dust.