How would you express the phrasing “Courtesy of [x]” in Japanese?

Question

I’m having a bit of trouble figuring out how to phrase this sort of thing. I’m thinking of this in the context of “acknowledging that someone has formally done a service for another”.

Examples might be: some kind of event presented to its guests courtesy of their sponsor, a delivery completed courtesy of a shipping service, a gift given courtesy of the help of someone else.

Alternatively, yourself providing a gracious service to another person—“courtesy of yours truly”? I’d like to get a comparison of what to do versus what not to do when trying to say something like this, if possible. I’m not sure how you would approach this sort of phrasing politely, versus politely-but-arrogantly.

I feel like this must be a grammatical construction/keigo thing, but I’m not sure whether it’s something you’d use sonkeigo or teneigo, etc. for?

Answer 1

You can use 提供 like this:

• この写真はAによる提供です。
  This picture is courtesy of A.
• 無料WiFi提供: A
  Free WiFi courtesy of A
• 本イベントのライブ配信はAの提供でお送りします。
  Live coverage of the event is courtesy of A.
• お菓子はAに提供していただきました。
  These snacks are courtesy of A.

Answer 2

You could use おかげで, for example (taken from WWWJDIC):

• 彼の尽力のおかげで、それは予期以上の成功であった。
  Thanks to his efforts, it was more successful than we had expected.

• 彼らのおかげで私はやっと元気になった。
  Thanks to them, I got well at last.

• この機会のおかげで私たちは大いに手間暇が省けた。
  Thanks to the opportunity, we were able to avoid substantial effort.

提供 relates to providing, offering or donating something, whereas おかげ implies a more causal relationship (and can also be either positive or negative, e.g. "I was late to work thanks to my broken alarm clock"). You can also use おかげさまで, which is commonly used to express thanks for someone's assistance.