Some doubts on configuration

[johjoh2k]

Good evening I have some question about Zimbra Configuration:
- in wich mode I can enable the request of SMTP authentication for users of domains managed locally by Zimbra? (I would like to activate in Microsoft Outlook SMTP Server Require authentication).
- I need to deactivate the opportunity to use alias name to login to Webmail, only true email account can login.
- I need to create an everyone@domain.com Mailing List at wich can write only (*@domain.com) all user member of domain.com, if a person reply the message come to admin@domain.com and if someone not member write the message it come to admin@domain.com, in wich mode is possible?

That's all, thank you in advance for support

[johjoh2k]

Another point, if I would activate relay of mail from external only for authenticated users where I must set it?

Thank you