When I worked as a sysadmin at Warner Bros back around 2001 our corporate mail was [email protected] which went to an AOL inbox (they made everyone eat the AOL dogfood). We realised that we owned a ton of domains including wb.com that didn't use email, so we set up some MX records and pointed them at a Solaris box running qmail and had our own wb.com addresses. I think I checked my official account maybe a handful of times the entire time I worked there.