I am attempting to develop a web interface using PHP which would allow any authorised user (specifically from the HR department) to update the Automatic Reply (Out of Office) of any active Exchange user/mailbox. I have successfully connected to the Exchange Web Services (Office 365) using php-ews (https://github.com/jamesiarmes/php-ews) and retrieved user mailbox configuration. However, I am unable to locate anything concerning Automatic Replies (Out of Office). Is there anyone who could provide examples or guidance on how this can be achieved?
You will need to use the GetUserOofSettings https://msdn.microsoft.com/en-us/library/office/aa563465(v=exchg.150).aspx and SetUserOofSettings https://msdn.microsoft.com/en-us/library/office/aa580294(v=exchg.150).aspx to do that in EWS. You will also need to use Impersonation to have the specific rights to do that make those changes https://msdn.microsoft.com/en-us/library/office/dn722377(v=exchg.150).aspx.
If your using Office365 your other option is you can use the Graph API to also do the same thing https://developer.microsoft.com/en-us/graph/docs/api-reference/v1.0/api/user_get_mailboxsettings which gets around any security hassles that EWS Impersonation might cause.