怎么用英语说：“我会办公室后，马上回复你的邮件”

I'll reply to you as soon as returning my office.

I'll reply your email as soon as I get back to my office.

回复- reply to ...
send back

I'll reply to your email as soon as I'm back to my office.

I will reply your mail right after my arriving at my office.
回复就是 reply

I will send the message to you as soon as i am back to my office.

I will reply your email right after I return to my office.