JMAP is a set of open Internet standard protocols related to handling email.
IMAP is a popular Internet message access protocol, as it is an application protocol that allows access to messages stored on an Internet server. Using IMAP, you can access email from any computer that has an Internet connection.
The reason to talk about IMAP because JMAP (JSON Meta Application Protocol) an open, standardized protocol has been established (RFC8620) for email clients.
JMAP It is mainly intended to replace IMAP, since this protocol is considered too old, too slow and complicated to implement. JMAP tries to solve these problems by making email processing easier and simpler and by providing more security.
About JMAP
The protocol is written by Neil Jenkins, Principal and UX Architect at Fastmail and Chris Newman, Principal Engineer at Oracle. Fastmail started working on JMAP in 2014 as an internal development project. The Internet Engineering Task Force (IETF) was also involved in the development of JMAP.
According to the developers, IMAP and SMTP are not only outdated and complicated, but also not suitable for modern mobile networks and high latency scenarios. This environment has led to a stagnation of good email clients and limited innovation from developers.
Many of the new clients and extensions are only for certain large email providers. Proprietary protocols have become the alternative to IMAP, but they also raise security and privacy concerns.
IMAP consumes many resources, it is difficult for developers to learn and does not work well for mobile devices with limited network. Combining IMAP with other protocols, such as SMTP, CalDAV, and CardDAV, for a full email client experience with calendars and contacts, is even more difficult for developers to learn and creates challenges for users in case of authentication failures partial.
Therefore, the developers believe that an open and modern solution is necessary. JMAP is presented as that long-awaited solution.
“As an open standard, JMAP is the alternative to proprietary email APIs that only work with Gmail. It's a long-awaited modern messaging standard that makes messaging more open to innovators like you," the JMAP website reads. The new protocol, developed by the Fastmail team, actually seems to fill in the gaps of previous open protocols connecting mail clients and servers and were not designed for the modern age.
“Cyrus's team has fully implemented JMAP as an open source server. The Perl developers at Fastmail have created a JMAP Perl server framework, and we have created a simple proxy server implementation for the JMAP protocol."
Of the characteristics of JMAP sand highlight:
- JMAP is more like NFS or filesystems with inodes instead of a name-based hierarchy, making renaming easy to spot and cheap to sync.
- Batch API Calls – Bundles multiple API calls into a single request to the server, reducing round-trips and improving battery life for mobile users.
- Data Flow Control – The client can limit the amount of data the server can send. For example, the command will return a "tooManyChanges" error if the limit set by the client is exceeded, instead of returning one million rows as can be the case with IMAP.
- No custom parser needed – Support for JSON, a well-understood and widely supported encoding format, makes things easier for developers.
- A backwards compatible data model: Its data model is backwards compatible with IMAP folders and labels similar to Gmail.
Fastmail already uses JMAP in production for its Fastmail and Topicbox products. It is also adopted by organizations such as the Apache Software Foundation, which added support for JMAP to its Apache mail server in version 3.0.
Finally If you are interested in knowing more about it, you can check the details in the following link or you can consult its development and code source on GitHub.