Webmail with IMAP/SMTP for use with mobile and desktop mail software. Contacts and calendar synchronization.
Spam filtering, greylisting, backups to Amazon S3, TLS(SSL) certificates.
SPF, DKIM and DMARC setup using the best security practices, including opportunistic TLS, strong ciphers, and HSTS. DNSSEC (requires additional setup). Exchange ActiveSync in beta.