[exim] Exim Third-party Support?

I have a customer who is about to do an exim migration for their
primary mail servers, but would like to have someone to call in the
event of a failure, much like commercial products. To this end, I'm
looking for a company that would provide a support contract or
per-incident support for exim. Can the list suggest any?

In addition, this customer, located in California, is curious
whether there are any US-located training options. I searched the
internets arnd couldn't find anything.


Thanks for your help,

Jason Hemmenway
Senior Technical Consultant
Taos