Encryption
One of my main requirements is proper OpenPGP support for end-to-end encrypted email.
That alone rules out Tuta Mail, since it does not support OpenPGP. Emails between Tuta users are encrypted, but when emailing someone outside Tuta, the only encrypted option is to send them a password-protected message.
That approach has two major problems:
- You need to exchange the password through another secure channel beforehand.
- The recipient has to open a link and enter the password on a page served by Tuta. This means trusting both Tuta’s server and whatever JavaScript it sends to the browser at that moment.
That level of trust impairs much of the point of end-to-end encryption.
This might come as a shock, but Proton Mail also gets disqualified here. While it supports OpenPGP, you cannot realistically use it without involving Proton’s web interfaces, which are required for things such as adding and trusting recipients’ keys, managing 2FA, and countless other tasks.
This again introduces a significant amount of trust in the provider and its server-delivered code, which, in my opinion, impairs the purpose of E2EE.
And yes, I know that Proton Bridge exists. But as someone who mainly uses his phone for security reasons, you cannot seriously tell me that running Proton Bridge in Termux, or using whatever other workaround you might come up with, is a reasonable option. It isn’t.
So I was left with Forward Email and mailbox.org as my two realistic options, since they both support IMAP and POP3, which I can use with a client of my choice while remaining in complete control of my private keys.
But here comes another problem: both FairEmail and Thunderbird for Android rely on a third-party app called OpenKeychain for their OpenPGP support.
OpenKeychain is no longer actively developed. Its maintainers say that reported security fixes and basic maintenance may still be performed, but the project has not received a code update since May 2024. It is also available only through the Play Store or F-Droid, both of which have their own issues that I will not expand on here.
Luckily, Forward Email has been working on its own email client. It currently works only with Forward Email accounts, but support for other providers is planned.
The client has built-in OpenPGP support, with private keys remaining on the device rather than being uploaded to Forward Email. This also avoids requiring another independently maintained application, such as OpenKeychain, Thunderbird, or FairEmail, as part of the encryption process.
Source-available and self-hostable backend
“BUT AN OPEN-SOURCE BACKEND DOESN’T MATTER!”
It indeed does not matter if your only reason for wanting it is to prove that the provider is not malicious, since you cannot realistically verify that the published code is exactly what is running on its servers.
What does matter is that Forward Email publishes its source code and documentation and provides the option to deploy the service on your own hardware.
This allows people to audit and test the software, discover vulnerabilities, and report them to the developers before they are exploited by bad actors.
Forward Email’s licensing is somewhat more complicated than simply calling the entire project open-source. Parts of the project use open-source licences, while other parts are released under the Business Source License. It is therefore more accurate to describe the project as source-available and self-hostable rather than unconditionally calling the entire backend open-source.
And, of course, software being self-hostable and having publicly available source code is a major advantage for many other reasons that are unrelated to security.
Support
Forward Email’s support has to be the best support I have ever received.
Both developers are active and available in the project’s Matrix room, and they are very helpful. They also take user feedback seriously, which I absolutely love to see.
Unlimited domains and aliases
Forward Email offers unlimited aliases on both your own domains and its vanity domains. This means I do not have to involve a third-party email-aliasing service.
Another major advantage is that these aliases reside on Forward Email’s main vanity domains. This is desirable because some websites reject or flag addresses from well-known aliasing services such as Proton Pass and SimpleLogin.
Using aliases on the email provider’s primary domains makes them less likely to be identified and blocked as disposable or forwarding addresses.