The person in charge is not here right now. Could you please send him an email?
The person you need to speak with is out of the office, so maybe you could send him an email.
この場合、次のような言い方ができますよ。
ーThe person in charge is not here right now. Could you please send him an email?
「担当者がいないので、メールしてもらえますか?」
ーThe person you need to speak with is out of the office, so maybe you could send him an email.
「担当者が外出中なので、メールしてもらえますか?」
ご参考まで!