If you get a error message about the site not beeing secure via SSL you dont have to worry, as long as you are on a website that you trust.
There are 2 kind of ssl certificates, selfsigned which are free and signed by a root entity which cost money.
The encryption level is basically the same, the difference is that on a selfsigned the company (in cases of mailservers its ABAKOMP) signs the encryption key, in paid ones, a company like Thawte, geotrust veryfies that the server actually is from the company that signed the cert.
So if you get a link from us to a website and you use SSL your browser will warn you that this certificate is selfsigned (we at ABAKOMP signed it).
If you dont want this to come up again you can just add the certificate to trusted links in your browser.
Read more here http://en.wikipedia.org/wiki/Self-signed_certificate