1. Avoid business risks - These days there is so much at stake, so no wants to send unencrypted emails. Without encryption any stranger can have access to the information which is contained in your mail.
2. Protection of confidential information - Email encryption protects confidential information such as your credit card number, banking account number, social security number etc. In case your mail is not encrypted some wrong elements can make use of your personal information for their ulterior motives.
3.Avoidance of Identity Theft - If any person gets hold of your username as well as password which you use to get to your email servers, he or she can read the emails which you send and also send false email messages on your behalf. This is referred to as identity theft and can be avoided if you go in for email encryption.
4.Repudiation of messages sent - Owing to the fact that it is easy to forge regular email messages, you can never really prove that a so and so person has sent you a particular message. This connotes that even if a person actually sent you a particular message, he can deny sending it. This has serious implications as regards to making use of email for the purpose of contracts, electronic commerce, business communications, etc
5.Unprotected Backups - The messages which you send are stored on SMTP (Simple Mail Transfer Protocol) Servers - outgoing mail servers. The backups of server disks encompass text copies of your messages. These backups can be present for years. So anyone who has access to the backup files can read your messages and use the information to your disadvantage even while you are thinking that you have deleted the message.