Send the document by/via email

[chitraaa]

Which preposition is correct in the following sentence written by me?
Despite my sending the certificate via/by email, I was given another letter again asking for the certificate.
Is there a better way of putting it?

 

[jutfrank]

You can use both but I'd suggest you use by.

 

[emsr2d2]

Were you really given another letter? That suggests someone handed it to you in person. I imagine it's more likely that you were sent/emailed another letter.