The Matrix protocol Matrix.org is a feature rich open source messaging protocol that’s very popular with developers, business and privacy leaning individuals. While there are a few Matrix clients, none have a mature, robust, or as feature rich interface as eM Client, and none integrate email.
This may be an excellent and not too difficult opportunity to expand eM Client awareness and the userbase substantially as there’s enormous free advertising via the Matrix portal, support and developer sites, and the massive face time increase of people using a popular chat protocol.
As well the feature limitations and stability issues in existing Matrix clients appear pretty nailed down in eM Client by comparison, which would make it quite popular if the protocol is not too difficult to integrate.