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...the table can be permissioned as appropriate (probably fine to restrict it to admin). Might be nice to restrict the u_email field to be unique, but that's just icing since it's enforceable manually by any reasonable admin.
Configuring aliases in the running system
The mail alias binding to groups happens at the Group level in Adminstration controls. Click a group, and then bottom of the dialogue page contains a tab called "Group Email Alias".
To configure a new alias , we need for the first time, somebody needs to open a ticket Service Request to YSS Client Accounts and make a request to bounce the mail to servicenow@yale.edu
Opinions on Service Now and inbound mail
Service Now isn't all that fantastic at handling mail, and incidents created from inbound mail are missing many properties that must be fixed before the recipient can handle the created incident. We also have spammable mail aliases, which then create bogus incident tickets we have to clean up. Eventually it would be nice to turn off inbound mail, or restrict it to a limited set of senders.