Looking on the internet deeply has found these results:

with reference your email is the most popular phrase on the web.

as per your email 1123 results on the web	with reference your email 15,340 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
It doesn't look like this phrase is very popular! The search could not find any examples on the internet.	My daughter Clare forwarded me your email. Observations can be sent to the Authority by fax, by post or email under reference number N... to the following address: You keep changing your email password. Well, if you're talking about the July 29th reference in his business email to his personal email, then you're too late. We tapped your phone, hacked your email. Reagan, I got your email. Let us go through your email list. Your email client is not supported.

as per your email

1123 results on the web

with reference your email

15,340 results on the web

More popular!

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

My daughter Clare forwarded me your email.
Observations can be sent to the Authority by fax, by post or email under reference number N... to the following address:
You keep changing your email password.
Well, if you're talking about the July 29th reference in his business email to his personal email, then you're too late.
We tapped your phone, hacked your email.
Reagan, I got your email.
Let us go through your email list.
Your email client is not supported.