伝えておきます

I'll let them know

→ 伝える
phrase Uncommon #15,737
I'll let them know The ~ておく pattern indicates doing something in advance or for future convenience. 伝えておきます is polite and often means “I'll tell them” or “I'll pass it on.”
JA: 明日の予定をみんなに伝えておきます。
EN: I'll let everyone know about tomorrow's plans.

警部の一人伝えておきます

I'll let one of the inspectors know.

— バジュランギおじさんと、小さな迷子 (2015)

彼にはそう伝えておきます

I'll let him know.

彼が来たらあなたの伝言を伝えておきます

I'll give him your message when he comes.

伝えておきます

I'll let them know.

— Брат 2 (2000)