Please expect an email from me later on regarding this issue.
There are many ways you can make this statement. It is always best to ensure that your tone is professional when stating you will respond later. You do not want your reader to feel as though you are pushing them to the side.
言いたい事を伝えるためには色々な表現方法があります。ちょっとしたニュアンスが感じられるよう、後で回答すると伝える際はプロフェッショナルなトーンを維持することが重要です。この表現は相手に対して顧みられていないと思わせないように配慮した表現となります。以下にいくつかの例をご紹介します。
"I will respond to your email at a later date." （あなたのメールには後日返答します）
"I will send a response at a more convenient time." （都合の良い時間に返信します）
"Please expect an email from me later on regarding this issue." （この件については後程私からメールをお送りします）
加えて、"I will email you with the answer later."（後ほど答えをメールで送ります）という表現も有用な選択肢となるでしょう。状況によって最適な表現は変わるので、上記の英語フレーズを参考にしてください。
"email you back" - this is the same as saying reply back by email
e.g. I'm waiting on him to email me back. I am impatient to hear his reply!
"email you back"（あなたに[メール](https://eikaiwa.dmm.com/uknow/questions/32887/)をします） - こちらは、reply back by email（メールで[返事をする](https://eikaiwa.dmm.com/uknow/questions/71905/)）という表現と同じです。
例文
I'm waiting on him to email me back. I am impatient to hear his reply!
（私は彼からのメールを待ってるの。彼の返事を聞くのが待ちきれない！）
*I will respond to you via email at a later date.
via means be means of. In this case you are saying I will reply to you by means of an email.
*Please expect an email on Friday with the answer.
This is a more specific way of expressing yourself. At least they know when to expect the email and it is more professional.
*I will respond to you via email at a later date. (後日メールで応じます)
"Via"とは「経由」という意味です。この場合はあなたは相手にメールで回答をすると言っています。
*Please expect an email on Friday with the answer. (金曜日に回答のメールをご期待ください)
これは自分を表現するためのより具体的な方法です。少なくとも相手はメールをいつ期待できるかを知ることができよりふさわしいです。
I need to chew that over and will get back to you by email
Sometimes a complicated question may deserve a complicated response and so, it may be prudent to carefully consider the question and respond in your own time by email. 'To chew something over' means to carefully think about the implications and repurcussions of something.
Informing that you'll send a reply email at a later date is fine if you are talking to a colleague or a friend. However, if you are replying to your professor or a superior, it's better to specify the date that you'll be sending a reply to show that you are professional about it. Just saying, "later" is informal and might show that the academic paper is not your priority.
Sorry I had no answer to hand...Give me some time to think and I will respond by email later!
We cannot always respond ..."on the spot" . We may need some time to think!
In this case we will "follow up" with an email, at a later date; clarifying everything asked.
"Sorry I had no answer to hand...Give me some time to think and I will respond by email later!"
私たちはいつも「即座に」返事できるわけではありません。考える時間が必要かもしれません。
この場合、メール、添付データ、質問などを後日確認しておきましょう。
"Sorry I had no answer to hand...Give me some time to think and I will respond by email later!"
答えを出す時間がなくすみません。考える時間をください。あとでメールで返事します。
Sorry, I can't tell you right now because I'm in a big hurry. I will let you know by e-mail at a later date.
I am not quite in the mood to discuss that right now. I will inform you by e-mail at a later date.
There had to be a reason why you could not answer the person concerning your academic paper on the spot in order to justify why you couldn't do so. One possible reason could be that you were in a big hurry to get somewhere. One other reason could be that you were not in the mood to discuss the issue at that time.
So, you may say:
Sorry, I can't tell you right now because I'm in a big hurry. I will let you know by e-mail at a later date.
or
I am not quite in the mood to discuss that right now. I will inform you by e-mail at a later date.
質疑応答にその場で答えられない理由があるはずです。とても急いでいる、もしくは、答える気分ではない場合もあるかもしれませんね。
そのような状況の場合は下記のように表現できます。
Sorry, I can't tell you right now because I'm in a big hurry. I will let you know by e-mail at a later date.
（申し訳ありません、今は急いでいるので答えられませんが後日メールにてお答致します。）
I am not quite in the mood to discuss that right now. I will inform you by e-mail at a later date.
（今現在はお答えできる状態ではないので、後ほど日を改めてメールにてお答え致します。）
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