It's important to note that your email is protected from eavesdropping only while in transit between your email program and our servers. If the message originated from or is sent to an address outside Neomailbox, then it may pass through the Internet in clear text.

Messages sent to another Neomailbox user never pass through the Internet in the clear.

If you would like to make sure that your messages to people using other email services are completely secure in transit, you might want to have a look at the PGP or GnuPG programs, which encrypt the text of your message before you send it.