There are lots of companies offering those services, you just have to find one who balances a good price, good service and availability for when you really need them. Many of them could offer an integral package, but some others just offer an specialty at a reduced price. E.g. I have a quite specialised service where I review packet captures for you: http://www.netstrikeforce.com
We use ZenDesk as the communications interface (over HTTPS, not over email) due to the nature of the information exchanged.
On the other hand you may want to have a look at managed cloud service providers where you've got a bunch of quite tenured sysads available 24x7.
Comments
There are lots of companies offering those services, you just have to find one who balances a good price, good service and availability for when you really need them. Many of them could offer an integral package, but some others just offer an specialty at a reduced price. E.g. I have a quite specialised service where I review packet captures for you: http://www.netstrikeforce.com We use ZenDesk as the communications interface (over HTTPS, not over email) due to the nature of the information exchanged.
On the other hand you may want to have a look at managed cloud service providers where you've got a bunch of quite tenured sysads available 24x7.