Well, sure. There are consulting companies that offer emergency service, as
well as independents such as myself.
Typically speaking, you are best suited having a relationship with someone
first (so that they have some idea about your configuration and that you have a
level of trust with them).
Dell ProSupport has a handful of wonderful Exchange Experts that have
always helped me out in the past. I have been very impressed how the
jump onto your case. They can get MS Support on the phone for free too.
Dell may not be your vendor, but you want to check with whomever you
vendor is.
Sam