If you have some accounts which needs to have full access permission on hundreds of mailboxes then following power shell command is for you. By using following steps you can add set of users to hundreds of mailboxes in single shot.
In order to use this command you have to perform below steps;
1. Create one csv file name it users.csv and save it to C:\ drive.
2. Type text "name" in first line. Please make sure that there is no space or any other special character after text "name" otherwise the command will not run.
3. Copy all user ids (of mailboxes) on which you want to add permissions after text "name" in same column.
4. Open Exchange Management Shell and type following command and press enter;
You can add more columns in you text file if you want by using comma ‘,’ and can reference it in the command as same as you are referencing the first column.
If you don’t have aliases or Ids and have only display names and these display names are in last name first name format such as smith, john then you have to add your names in your .csv file like this “smith, john”
if you want to do opposite and wants to add full access permission for lots users on one mailbox then following will be your command