This article will help to resolve Nagios login screen redirecting to itself which occurs due to a mismatch in the time zone can cause the Nagios login screen to redirects to itself after entering the login credentials.
In summary, Zimbra does not enforce any strong password requirements for a user account. This poses a risk of the account being compromised and ultimately used for spamming. This article will help to configure Secure Password Policy on Zimbra.
This article will help to fix "Outlook conflicting or unsupported encryption capabilities" by simply turning off e-mail address matching for certificates and it depends on the version of Outlook you are running.