If your organization uses lots of shared mailboxes in Exchange (On-Prem or Office 365) one thing you probably do a lot of is grant full access and send as permissions to shared mailboxes. Being a busy admin, I like one liner scripts and shortcuts. I decided to use Excel's concatenate function and a really simple spreadsheet to automate adding users to have rights to shared maiboxes.
Add your values to Mailbox Alias and User Alias and drag down script result field. Select and copy the results from the results column. Then open Exchange Management Console and paste in all of the one liners one by one to test or all at once if you feel good about it.
How it works:
The one liner PowerShell script we are using is:
Add-MailboxPermission -Identity Mailbox Alias -User User Alias -AccessRights FullAccess
Then we are using Excel's Concatenate function to put it all together.
=CONCATENATE("Add-MailboxPermission -Identity ", A1," -User ", B1, " -AccessRights FullAccess")
Here is a screenshot and you can download a sample spreadsheet here - Download Mariannes Quick and Dirty Exchange Script Maker Full Access and Send As Permissions