When a client logs into the FlexPoint portal, there should be an option to setup Time-base One Time Password (TOTP) using an authenticator app. It is more secure than emailing a code and is still accessible if having email delays. There would need to be a method to obtain access if they can't use TOTP (aka phone dies and they don't have a backup of their authenticator app data). The common method is to provide them about 10 recovery codes they can use, each code can be used 1 time. You may want to allow them to reset the TOTP code via email, but I would delay the email 1 day for security purposes.