I have create Zimbra VM in my home for testing.
All default on ubuntu.
Seems like all working.
But i cant add external mailbox check on account in webgui. I have filled all fields and press "test settings" but i get error message like this.
Zimbra: ?????????: ??????? ??????
So something with sertificates.
Its related to ZimbraVm or remote VPS ? (im using vps as mail and web server)

Please ask all you need to help me solve it.