いろいろとありがとうございました。
I appreciate everything you've done for me.
As always thank you for the various things you do.
As always thank you for the many things you do.
Thank you for everything as always.
As always, thank you for the many things you do.
Thank you for your many kindness to me.
Thank you for your many kindnesses to me.
Thank you all so much.
あら、ありがとうございます。
Thank you for your letter.
Thank you for your letters.