Definition - What does Email Encryption Gateway mean?
An email encryption gateway is an email server which is used to encrypt outgoing mail and decrypt incoming mail. This is an appliance-based security solution that is placed between the enterprise network and the outside network such as the Internet.
Aside from encryption and decryption of email, these gateways often also serve as spam blockers and scan for viruses.
Techopedia explains Email Encryption Gateway
An email encryption gateway secures all email leaving the enterprise network according to configurable encryption rules which eliminate the need for client software and further user intervention.
So from the user’s end, they are simply sending email normally; this email is then captured by the gateway, encrypted and then sent on its way. Incoming emails that are encrypted get decrypted so that they can be read and also scanned for viruses.
In recent years, the email encryption gateway has also become virtualized, meaning that there are now virtual solutions which do not require actual gateway hardware. Instead, the gateway is a virtual machine which exists in the enterprise network somewhere and all emails simply need to be routed through it for it to do its job.