IMAP and SMTP IETF Standards
The IETF is a large, international community of network designers, operators, vendors, and researchers concerned with the evolution of the internet architecture and the smooth operation of the internet. This community has put in place the basic designs for operation of the internet including the transport of email over the internet, and continue to enhance these through various working groups.
Mobile Gateway supports two of the primary mechanisms defined by the IETF for transport of email over the internet, IMAP4 and SMTP.
Internet Messaging Access Protocol Version 4rev1 (IMAP4) - RFC 3501
The IMAP4 protocol is an email access protocol that allows an email client to access and manipulate messages stored on a remote message store.
Whereas the Post Office Protocol (POP3) allows basic download of messages, the IMAP4 protocol is more flexible in that it maintains a message on the mail server and allows message status changes to be exchanged between the client and the server. These changes can be then synchronized with multiple email clients (e.g. a mobile client and a desktop based client). In this way, the IMAP4 protocol is perfect for use on mobile phones.
Message status changes supported by IMAP4 include:
- New
- Read / Unread
- Deleted
- Filed
By using IMAP4, Mobile Gateway is able to use an industry standard supported by many devices to manage the communication between the device and the variety of back-ends available in the market.
Whether it is a simple POP3-based mail service, a more advanced IMAP-based ISP service, or a proprietary business mail service (e.g. Microsoft Exchange), Mobile Gateway can talk in a single language to the device and translate to the back-end accordingly.
Simple Mail Transfer Protocol (SMTP) - RFC2821
As the name suggests, the SMTP protocol is a simple method of transferring or sending a new email between an email client and an email server.
The SMTP protocol is supported by all mobile devices offering an email application and, as with IMAP, allows Mobile Gateway to manage a single communication protocol to the mobile device whilst managing the appropriate connection into the back-end mail server.
