Since it wasn't delivered directly person-to-person, we couldn't guarantee it one hundred percent, but it is recorded as having been delivered.
ご質問ありがとうございます。
"Since it wasn't delivered directly person-to-person"=「直接、対面で配達されたのではないため」
"We couldn't guarantee it one hundred percent"=「確実に保障はできませんが」
"but it is recorded as having been delivered."=「しかし、配達された、というふうに記録はされています。」
ご参考に!