Sendinc is described as 'Secure email made simple' and is an website in the Security & Privacy category. There are more than 10 alternatives to Sendinc, not only websites but also apps for a variety of platforms, including Linux, Windows, Mac and Android. The best alternative is ProtonMail, which is both free and Open Source. Other great sites and apps similar to Sendinc are Tutanota (Freemium, Open Source), mailbox.org (Paid), Mailfence (Freemium) and Enigmail (Free, Open Source).
mailbox.org offers a secure e-mail account for home and business use. The domain name, firstname.lastname@example.org, is easy to remember and can be understood anywhere in the world. They have been operating e-mail accounts for more than 20 years and are a highly reliable service provider.
We believe that Internet privacy is an absolute and definitive right. Online privacy matters and is just as important as offline privacy. Some people say that the loss of privacy is the price we must pay for security.
Mailpile is a modern, fast web-mail client with user-friendly encryption and privacy features. The development of Mailpile is funded by a large community of backers and all code related to the project is and will be released under an OSI approved Free Software license.
Mailvelope is a browser extension that allows to exchange encrypted emails following the OpenPGP encryption standard. Mailvelope integrates directly into the Webmail user interface, it's elements are unintrusive and easy to use in your normal workflow.
FlowCrypt (formerly CryptUp) lets you Encrypt Gmail with PGP in 60 seconds. Easiest end-to-end encryption for Google Email. FlowCrypt supports attachments, drafts, conversations.. just like Gmail you are used to.