Linear uses a service called SendGrid for email forwarding. SendGrid is one of the world's largest and most trusted email forwarding services. SendGrid primarily delivers your emails through a TLS-encrypted connection, provided that the recipient's email server supports it. All the major and well-known email programs, such as Outlook and Gmail, support this encryption protocol.
You can read more about SendGrid's security here and here.
For example, signed mandates sent as email attachments also cannot accidentally end up with the wrong person, as they are automatically sent to the same individual who has authenticated with bank credentials and electronically signed the agreement.
Although GDPR does not require emails to be encrypted, Linear only uses the world's largest and most trusted partners for email forwarding. Linear adheres to GDPR regulations in all its activities, and security is our top priority.