Link for Sap Inbox

Dear Friends , I want to do hardcode the SAP INBOX link in my coding part . And Want to send the same link in my outlook mails .

i.e Once the user click from the outlook then after entering the crenditials , The user able to connect to his SAP inbox .

I tried alot but unable to find the http link for SAP Inbox . Please suggest me the tcode or the method by which I can find the link for Sap Inbox and SAP porttal .

I will do the coding like below .

If system is DEVELOPMENT ,

Then link = Link1

Elseif System is Quality ,

Then Link is Link2

Elseif System is Production ,

Then Link is Link 3 .

ENDIF.