I know what you mean.
I understand what you mean.
Got it. （非常口语化，适合于很熟悉亲近的人之间。）
I do not quite understand what you meant.
I have some problem understanding what you meant.
Please kindly find the attached ……
Attached please kindly find the ……
Enclosed is the ……, please kindly find it.
Attached you will find……
I have received your email (yesterday/last week/this morning……).
Your email has been received.
Thanks very much for your early reply.
Thank you for your email.
Could you please put it in a clearer way?
Could you please explain it in detail?
Could you please further explain it?
What do you mean exactly by saying……？
Contact me if you have any problem.
If there is any uncertainty, feel free to contact me.
Call me if you have any problem.
Please let me know if anything needs to be improved.
Your advice/suggestion will be greatly appreciated.
I will further modify it.
I will further check it.
Once confirmed, I will let you know immediately.
Once confirmed, I will notice you ASAP.
（*ASAP=as soon as possible 尽快）
I’m looking forward to your early reply.
Your promote reply will be greatly appreciated.
Your early reply will be highly appreciated.
I hope everything goes well with you.
I wish you all the best.
I want to talk to you over the phone regarding issues about report development and the XX project。
Shall you have any problem accessing the folders, please let me knows。
Thank you and look forward to having your opinion on the estimation and schedule。
Look forward to your feedbacks and suggestions soon。