Implementing multi-factor authentication (MFA) provides a powerful defense against unauthorized access, as it requires users to provide two or more verification factors to gain access to resources, thus protecting against compromised credentials. Email encryption is a security measure that protects the contents of emails but does not secure access to collaboration tools and resources. While limiting connection times could potentially reduce the window of opportunity for an attack, it would not be practical for collaboration needs and does not strengthen authentication methods. The frequency of changing passwords, without the additional step of verifying the user's identity, may be less effective against sophisticated attacks.