I am trying to migrate the Outlook Online Auto-Complete Cache from one O365 tenant to a new one

[Jattar74]

At the moment I am migrating users from one O365 Tenant to a new one in a new domain. I have had the VP's complain about losing their auto-complete cache for Outlook. 
However I have yet to discover a tool, script, or even C# source code that allows this to happen.

Is there a way to do this?

Also, I am tasked with attempting to allow cross tenant sharing of resources, such as the address books and calendars. I realize there is a "Share with Outside Organizations" Feature, however I am looking for an automated way to do this at the admin level that does not require Users intervention as VP's are not very technical and they do not want to have to put effort into such tasks. 

Thank you in advance.

[#2]

Hi @Jattar74 , this question would be best managed in the Exchange community: https://techcommunity.microsoft.com/t5/exchange/ct-p/Exchange and adding my peer, @Greg Taylor - EXCHANGE who can take a look at your Outlook/Exchange migration question.

Thanks, Mark 

[#3]

As @Mark Kashman said - post this over in the Exchange Community and let the collective over there suggest how to solve these if they can.

[#4]

Thank you and my mistake. I misunderstood the original email I received. I will repost in the correct area.@Mark Kashman