FastMail started with IMAP in 1999 when it was still quite new. We
have been involved in the standards process, and have watched while
non-open protocols led the way on features, usability and reliability.
We pride ourselves on the standards compliance of our server, but we
have been frustrated by the lack of progress in the third-party client
experience available to our users.
The fragmentation of server support for newer IMAP features means that
clients either have multiple implementations of everything, with the
complexity and bugs that involves, or fall back to
lowest-common-denominator behaviour. Extending IMAP further just makes
this situation worse.
FastMail is my e-mail provider of choice. I have used them for a year
now. And I think they are one of the companies that know better than
most what pain in the ass e-mail and IMAP / SMTP is. They are doing
something great here.
FastMail have their own protocol, JMAP. And they have made it public to
have more interoperability, beyond IMAP and SMTP.
IMAP and SMTP are protocols from the past, before mobile, before push
notifications. JMAP is made to address all of that. One of mine
favorites is the support for batch operations. It means that they can
bundle multiple operations in one API call.
A great protocol, I hope more providers on both ends start supporting