To get a CSV file, from you exchange with full access and send as permission, from all you mailboxes run these commands:

Full Access

Get-Mailbox | Get-MailboxPermission | where {$_.user.tostring() -ne “NT AUTHORITY\SELF” -and $_.IsInherited -eq $false} | Select Identity,User,@{Name=’Access Rights’;Expression={[string]::join(‘, ‘, $_.AccessRights)}} | Export-Csv -NoTypeInformation c:\mailboxpermissions.csv

Send As

Get-Mailbox | Get-ADPermission | where { ($_.ExtendedRights -like “*Send-As*”) -and ($_.IsInherited -eq $false) -and -not ($_.User -like “NT AUTHORITY\SELF”) } | Select Identity, User, Deny | Export-CSVc:\sendas.csv