How to say "reply to an email" in Japanese?

Question

What is the correct word to use for "reply" in phrases like (a) "I will reply to your email later" or (b) "I forgot to reply to your email."

I saw instances such as 回答, 返事, but

1. I am not really sure which one is correct.

2. If they are correct, I would like to know how to use them in sentences such as (a) and (b)

3. I would like also to know if saying メールに答える for (a) and (b) would be a correct wording.

Answer 1

「返信」or 「返事」are often used as "reply" in general.

(1) 「返事」「返信」「回答」

• 「返事」 is a word that is often used in casual emails, LINE etc.
• 「返信」is a word used in more formal situations, includes business setting. You can also use it in casual emails.
• 「回答」is often used when the other party asks you some specific questions/inquiry, such as meeting time and number of stock etc. I wouldn't use「回答」in casual emails.

(2) Example sentences

Casual emails (To friends)

(a) あとで返信するね。/あとで返信する〜！

(b) ごめん、この前もらったメールに返信するの忘れてた。

More formal setting

(a) 後ほど返信いたします。/後ほど返信します。

(b) お返事するのを忘れていました。/先日いただいたメールに返信するのを失念しておりました。

Example sentences with 「回答」

ご質問いただきました件につきまして、以下、回答いたします。

Below are the answers to your questions.

Just a quick note: In business setting, even if you forget to reply, normally you don't mention "I forgot." It's considered rude. So you just need to explain the reason for your late reply, without the need to say “I forgot”

(3) I wouldn't say メールに答える. You could say メールで聞かれた質問に答える。