Find all messages of the last 2 years by reciepient/sender

[fewbyli]

Hi, 

in a few month i will have a lawsuite and i need to catch all emails which i recieved from email address removed for privacy reasons or i send to email address removed for privacy reasons 

I would like to get an email thread as PDF for printing it. We are Using MS365 including Exchange online.

Any tips for exporting? The outlook search is showing me only 50% of the emails. 

Thanks for your help

[#2]

You can use eDiscovery/Content search for that: https://learn.microsoft.com/en-us/microsoft-365/compliance/ediscovery-content-search?view=o365-world...
Keep in mind that you will only be able to search for/export messages currently residing in the mailbox(es) in question. Messages that have already been deleted will not be included. In order to meet legal requirements, you very likely need to place the mailbox(es) on hold, in order to avoid further losses.