POP3, IMAP4, and SMTP are standard email protocols that allow different email systems to communicate with each other. These protocols also allow email users to check and send email via desktop email software like Microsoft Outlook and Mozilla Thunderbird, as well as wireless devices like Blackberry, Treo, and Sidekick.

POP3 - 'Post Office Protocol' (Version 3)

The most popular way for users to access their email is through the POP3 protocol. When a user checks for new email messages using POP3, the messages are downloaded to the user's local computer and into the email client of their choice. Then, in most cases, the messages are removed from the mail server. This method is well-suited for users who have limited storage space on their email provider's mail servers or those who don't want to store email messages online.

Most email clients, like Microsoft Outlook and Mozilla Thunderbird, allow users to leave email messages on their email provider's mail servers, even after the messages have been downloaded to the user's local computer. For users who want to download their messages to their local computer, but also want to access their messages online via webmail, this option provides the most flexibility.

IMAP4 - 'Internet Message Access Protocol' (Version 4)

IMAP is another popular protocol for accessing email messages. With IMAP, instead of downloading new messages to the user's local computer, the messages continue to be stored on the mail server. When users access their email through an email client such as Microsoft Outlook or Mozilla Thunderbird, they are working directly with the messages stored on their mail server. For example, when an IMAP user composes and sends a new email message, that message will be stored in the Sent folder, which is stored on the mail server.

IMAP is a convenient option for users who need to access their email online from multiple computers and locations—but prefer to use email client software instead of webmail. Because all messages—including sent messages, drafts, and messages stored in mail folders—are stored on the mail server, they are accessible from any Internet-enabled computer with pre-configured email client software. IMAP can also be useful for wireless email users who need access to their email with their wireless device, but do not want to overload their device's memory by downloading and storing messages locally.

Our IMAP server provides real-time push support for IMAP applications, alerting you the second you have new mail. Your IMAP application establishes a connection to our system and then sits in an idle state waiting for our servers to tell it when there is new mail. It can even watch for new mail in several folders at once and alert you the second that new mail arrives, which makes it very powerful for folks on the go.

SMTP - 'Simple Mail Transfer Protocol'