What Is a Mail Proxy?

An email proxy or mail proxy is a software program that works between the email client and the email server. The most common purpose for a mail proxy is to control spam, but there are other uses as well.

Function

• As the term "proxy" indicates, the mail proxy acts in place of your email client or program, such as Outlook or Thunderbird, in interactions with the email server. The server storing the mail is generally on the Internet, operated by an Internet service provider.

Process

• The client sends a request for email, and the request goes through the proxy. The proxy then sends the password and email address to the server, then retrieves the email. The mail proxy marks mail as spam, using one or more of several filtering methods. These can include whitelists or blacklists the user generates, keywords, or statistical algorithms.

Results

• The proxy then sends the marked email to the email client, which sorts the spam from the legitimate email according to the guidelines the user has programmed. Often the default for spam is that it is sent to a trash folder, then deleted after a specified amount of time. Proxies also can provide anonymity, bypass other proxies and hide an IP address.