Microsoft Exchange Server, Zimbra Collaboration Suite, Mailvelope, NeutronMail, Encipher.it, SCRYPTmail, AnonyMail, OnionMail, Kerio Connect, OBM, Wimi, Shazzlemail, GPGMail, SIGAINT, Lockbin, Enigmail, AnonymousSpeech, Kopano, IceWarp, CrossBox, systemli.org, Fripost, WebPG, LuxSci, Sendinc, Contactoffice, PolarisMail, ZWOOKY, SMBMail, Sanwhole Exchange, Walnut Secure Email, Secure Exchanges, Secure Gmail, PEPS, MailShogun are some alternatives to Kolab Now.