Thank you for your mail. Please write it to me again in English.
Thank you for your mail. Please send it to me again in English.
「ご連絡ありがとうございます。」(メールの場合)
"Thank you for your mail."
「残念ながら意味がよくわかりません。英文でもう一度送っていただけますでしょうか?」
"Unfortunately I cannot understand it very well. Could you please send it to me again in English?"