Protect specific emails from deletion

Question

Is there any plugin or addon that would allow me to protect emails (on Gmail) from deletion? So it would ask me the password for deleting protected emails.

Answer 1

No. Gmail webclient is more of a IMAP client to the mail on servers - There isn't any plugin which can prevent this.

Answer 2

No, there is no way to prevent it.But there might be a way around it.

Backup!
Create an another mail account, and forward all important mails to it as backup. Make sure you are the only one with the password. It is also possible to create a filter which will forward all received mailed with specific values, e.g. mail subject contains word "IMPORTANT".