I want to create multiple Email to case routing addresses, but I want the Email Id to be same for all of them, so that the customer has to send mails only to one Id.
3 answers
You can have multiple email-to-case routing addresses, but they can't all share the same email address. If you have email address 1 test@test.com, 2 with test@test.com, and 3 with test@test.com, there would be no way to determine the final destination.
However, if you wanted say three difference emails that eventually pointed to 1 email-to-case, that is possible.