Yes, you can use FireMail as your primary email program, or use it as a complement to an existing email program when you need to use email encryption. Since FireMail uses IMAP to retrieve your emails then you'll always have a copy of your email in all locations.

EncryptUs is really easy and totally automatic to use. Just send an encrypted email using the padlock send icon, and any recipient also using FireMail will be able to read that email when it's decrypted upon entering their device.

No, your emails are only encrypted during transit. Once an encrypted email is downloaded to your Firemail, it is decrypted so you can read and store it (and search for it).

IMAP stores the email on the server and downloads it when requested. Your email will be decrypted in your email program but will remain encrypted on the server.

Another point to note is if you are receiving encrypted email, and decide to read messages via webmail, you won't be able to read them. They need to be downloaded to Firemail where they are decrypted.

Yes, only if you want to send encrypted emails between each other. Otherwise all your emails will be sent as they normally are. The need for the recipient to also have EncryptUs installed is a pretty common complaint of email encryption software, hence why EncryptUs doesn't force it or change the way you work. EncryptUs does add a byline to the email footer of the free version which states they can install the software to have encrypted emails between each other. This can be removed upon buying a license.

Yes, this is very important if you have purchased your own key. You can do this easily by selecting the backup option and you'll be give a list of words to write down, or a QR code to copy. If you lose these key words or QR code you won't be able to decrypt your emails.

EncryptUs makes sending emails safe. It does this by encrypting the contents of each email so that only the recipient can read it. The email cannot be read by anyone else while it is in transit.

Working with EncryptUs is simple. Once it's installed, you still send and receive emails as you normally would. There's nothing special or different you need to do. EncryptUs operates invisibly in the background, encrypting and decrypting emails automatically as it manages your cryptographic keys.

EncryptUs works when someone else you send an email is also using EncryptUs, then all your email communications together are automatically encrypted.

If you send an email to someone who doesn't use EncryptUs, then your emails are sent as usual. ie. Not encrypted.

Simple and secure!

Have you ever emailed personal details, finances, credit card details etc to someone via email?

You probably didn't know, but sending email is very insecure.

Your email usually passes through a large number of computers, other networks and countries, leaving a copy of itself each time. At all times your messages can be read by the people who are in charge of these computers and network equipment (and in many cases your government).

Because email is sent in an easily readable format and is often stored for years, it has no protection from prying eyes meaning any personal information you send could be hacked years into the future. Messages you thought were deleted years ago may still be sitting on servers around the world.

So, in a nutshell...

* email is sent in a plain readable format.
* copies of your email are left on servers.
* stored email may be read in the future.

This is why you should encrypt your email.

Encryption is the science of securing communications against eavesdropping by converting the content of a message into a code, or cipher, which can only be unlocked using a secret "key".

In practice, when I send a message to a friend, it is encrypted, that means it is changed in a way that nobody can read it. Only my friend is able to change it back to the original message (decrypt it), and will then be able to read it.

EncryptUs is installed as part of FireMail, so it encrypts your outgoing email when you press send an email, it uses the inbuilt private key and encrypts the email and sends the email to the recipient. When the receiver receives the email, the email is automatically decrypted. If the sender has purchased their own key, then that is used instead of the inbuilt free private key.

With the very strong encryption used by EncryptUs, generally speaking it would take computers millions of years to crack your messages.

Using recognized industry standard encryption, EncryptUs goes a step further and makes email encryption usable for everyone. It sits in the background automatically encrypting and decrypting your email (in case you were not aware, email encryption has traditionally been difficult to setup and cumbersome to use).

Industry Standard Encryption
EncryptUs uses Elliptic Curve Cryptography (Curve 25519). If you want to fry your brain with some reading about encryption used in EncryptUs, try the links below.

See Elliptic Curve Cryptography

EncryptUs uses Elliptic Curve Cryptography (Curve 25519). It would take computers millions of years to break the encryption used in EncryptUs.

EncryptUs is not reliant on a central server, so cannot be taken down or tampered with.

When you verify your email address in EncryptUs, a pair of encryption keys are generated.

A private key - which is kept on your phone in the a(href="https://developer.android.com/training/articles/keystore") Android Keystore System.
A public key - which is made public. When you send an email, the email message is encrypted using Elliptic Curve Cryptography encryption. This algorithm generates a public and private key for each user. Public keys are exchanged and a shared secret calculated. From the shared secret, secret keys are generated for the encryption and authentication of the email.

Once the recipient receives the encrypted email message their private key is used to decrypt the email.

Elliptic Curve Cryptography is very fast, saves processing power, energy and relies on much smaller computation to achieve the same level of encryption as existing methods.

The keys are generated on your Phone and stored in the Android secure vault.

A license give you your own private key instead of the free private shared key used by everyone. Also you'll be able to disable and edit the outgoing footer of the email.

The license is an annual cost, but if you don't renew it will still work for you, but just without the extra features.