E-Mail Services With Encryption & Privacy Protection

Tutanota is an email service with a focus on security and privacy through the use of encryption. Tutanota has been in operation since 2011 and is based in Hanover, Germany. Accounts start with 1GB storage with their free plan. Tutanota doesn't allow the use of third-party email clients. There are plans to allow Tutanota pull email from external email accounts using the IMAP protocol. Email import is currently not possible. Emails can be exported individually or by bulk selection. Tutanota does not allow for subfolders as you might expect with other email providers. Tutanota is working on a desktop client and they have an app available in F-Droid. They also have their app in conventional stores such as App Store on iOS and Google Play for Android.

Mailbox.org is an email service with a focus on being secure, ad-free, and privately powered by 100% eco-friendly energy. They have been in operation since 2014. Mailbox.org is based in Berlin, Germany. Accounts start with 2 GB of storage, which can be upgraded as needed.

Posteo is an email provider that focuses on anonymous, secure, and private email. Their servers are powered by 100% sustainable energy. They have been in operation since 2009. Posteo is based in Germany and has a free 14-day trial. Posteo comes with 2 GB for the monthly cost and an extra gigabyte can be purchased for €0.25 per month.

Disroot offers email amongst other services. The service is maintained by volunteers and its community. They have been in operation since 2015. Disroot is based in Amsterdam. Disroot is free and uses open source software such as Rainloop to provide service. Users support the service through donations and buying extra storage. The mailbox limit is 1 GB, but extra storage can be purchased 0.15€ per GB per month paid yearly.

ProtonMail is an email service with a focus on privacy, encryption, security, and ease of use. They have been in operation since 2013. ProtonMail is based in Genève, Switzerland. Accounts start with 500 MB storage with their free plan. Free accounts have some limitations and do not allow the use of the ProtonMail Bridge, which is required to use a recommended email client (e.g. Thunderbird) or to search email by body text. Paid accounts are available starting at €48/y which include features like ProtonMail Bridge, additional storage, custom domain support, and more.

StartMail is an email service with a focus on security and privacy through the use of standard OpenPGP encryption. StartMail has been in operation since 2014 and is based in Boulevard 11, Zeist Netherlands. Accounts start with 10GB. They offer a 30-day trial.

Watchlist Of E-Mail Services
(NOT RECOMMENDED YET)

Criptext email service utilizes the open source Signal Protocol library, which protects your privacy and security throughout your entire Criptext experience. All your emails are locked with a unique key that‘s stored on your device alone, which means only you and your intended recipient can read the emails you send.

E-Mail Services With Serious Security Issues
(THE USE IS STRONGLY DISCOURAGED)

Communication is not secure with the following services. Be aware of the danger of their use. With the below mentioned services, you have no control over which unauthorized or unwanted individuals or organizations may track your communications with certain or even full details. In addition, you give up the control over what happens to your private data and how they are used in favor of unknown groups and also against you. Furthermore, users expose themselves to dangers of cyber attacks and other criminal activities with the possibility of personal and financial damages. Please read the linked articles to learn more about the shortfalls.
The following list is not complete. It only shows a selection of popular services.