Kurrier
Workspace for email, calendar, contacts and storage
...It’s designed to sit on top of standard protocols and services rather than replacing them, connecting to mail providers through IMAP/SMTP and supporting outbound delivery options such as SES or popular transactional email providers. For personal information management, Kurrier syncs calendars via CalDAV and contacts via CardDAV, making it compatible with common clients across desktop and mobile ecosystems. It also adds an integrated “Drive” concept that can use WebDAV locally and is intended to support S3-compatible storage backends as the project expands. The UI aims to feel fast and cohesive across modules, with features like multiple identities (useful for multi-domain or multi-sender setups) and organizational tooling such as labels.