Necessity of SSL certificate for mail server for security

I have to secure my site with a password. Do I still need an SSL certificate for the mail server?

Yes you do need an SSL certificate for the mail server. Secure Socket Layer basically is a protocol for transferring private or important documents over internet e.g. private chats, money transactions. Basically, many organizations need SSL simply for confidentiality, e.g. encryption. Data security of your credit card numbers, other account details are encrypted with the help of an SSL certificate. Customers and count on the site without any problem. Not every website has these certificates but those who have are fully secured.