fix(mail): Support recipient with empty Name

[slax57]

Problem

When sending an email to an address that has no first and last name, it creates a contact with no first and last name.

Solution

We should use the part of the email before the @ and split it between dots to fill the first and last name.

How To Test

Send a message to an email not in your contacts.

Alternatively, this can be tested locally using the sample curl command here and clearing the To.Name field.