"A lot is done by e-mail."
And your sending email over just HTTP? You sending directly to some box using smtp? Not inside a TLS connection?
Who do you use for email? Google provides https for your email, etc.
Even if you run a vpn to your home.. Where is the email server.. That traffic is going to be in the clear from your home network or where ever the vpn end point is to the email server. And then when that email gets sent to dest, its going to be in the clear as it gets sent to the recv server.
Email is sent all over the internet in clear.. Not sure why you would be worried about the traffic between you and the server, when from that server to where you sending is open
You could always encrypt your email if you worried about the security of email. But a vpn does not really solve that issue in general.
To correctly secure what your worried about, we need to understand what it is your worried about. Sure a vpn would hide the traffic from the local network your on to where the vpn endpoint is. But what are you moving over the local network that would be of concern.. Most anything that would be of concern should already be inside a endpoint to endpoint encryption method. HTTPS for example. This secures your traffic from your client to the endpoint. So a VPN does not really provide any more security for that sort of connection.