Is there a way of ensuring email security every time?

When the setting on the network computer I use was changed by someone without my knowledge I could not access my email accounts. I had to use an alternative method to send email by opening another account.Even then, that browser was changing the size of the font and page width etc; but I got the mails out. The matter which concerns me is if there is any security on a shared network.I have read that even keystrokes can be monitored.How can one tell if this is the case on the computer you use at work or elsewhere? How can you get a lock to show when you are writing an email or other personal data that you do not wish to share with others? Please help.
Is there a way of ensuring email security every time?
there is only one true way, but it verifies the machine that's sending it, if someone else is sitting at that machine, using that account, there's little one can do to secure that.


the method is a sender certificate. Certificates can be purchased from domain registrars (godaddy, networksolutions, register.com etc).


There are several categories of certificates, but their purpose is always the same, verification. They are most commonly used for https sites.


what you can do is purchase a mail sender certificate and then any email sent in your name can be encrypted using your certificate with the same security that an https site would have.


I'd have to know more about your email client to be more specific.