XryptoMail is an email client for Android supporting the following features:

Push IMAP IDLE and POP support
WebDAV support
Multiple mail accounts support
User OAUTH2 authentication support
Message list sorting by date, arrival, sender, read state etc
Message list with different backgrounds for read state, encryption and stealth etc
Message refiling and flagging
Message view gesture support with Pinch-to-Zoom
Message view/forward with html content support
Message send signature support
Multiple