Password-Protected Messages Expiration - How Does It Work?

I want to know what exactly the following means:

“Password-protected messages expire in x days”

Messages that you send to people who don’t have encryption enabled on their end will require that you add a password to protect them.

Such messages will be encrypted on your end using the password, stored in encrypted form on FlowCrypt servers, and then served to the recipient.

We expire and delete these emails within 90 days of sending for both free users and Enterprise users who use Shared Tenant FES. We do this to protect users who may have used a weak password. However, Enterprise users who run their own server infrastructure can choose the expiration time.

Unfortunately, many people will use fairly weak passwords. Given enough time and resources, someone could crack the messages with brute force. That’s why they expire. Once expired, they’ll be deleted from our servers.

Messages sent between people who use encryption don’t expire, because they are delivered over email like any other message. Additionally, they are typically more securely encrypted.