The content of the website?
What is copylefted? The JavaScript of the webmail?
It is common practice. Whether it is acceptable is up to you.
If you do not use end-to-end encryption (typically GPG), the email provider
can read your emails. Some providers propose to store your emails encrypted:
see https://posteo.de/en/site/encryption for instance and notice (a
See that recent thread: https://trisquel.info/forum/free-email-providers
(heyjoe's messages were removed; that is why, sometimes, the sequences of
messages apparently makes little sense).
