Searching Exchange 2010 Mailboxes with PowerShell
If you don’t have access then assign the role to the required user account :
New-ManagementRoleAssignment -Role "Mailbox Import Export" -User administrator
This will search every mailbox for messages containing the word FINDME in the message body and export them to the administrator mailbox in a subfolder called Results
Get-Mailbox -ResultSize Unlimited | Search-Mailbox -SearchQuery "Body:'*FINDME*'" -TargetMailbox administrator -TargetFolder Results
If you want to search a single mailbox using the body
Search-Mailbox -Identity user1 -SearchQuery "Body:'*FINDME*'" -TargetMailbox administrator -TargetFolder inbox
You can also replace the word Body with Subject, From, To etc…