Mail / DNS Issues

We are having DNS issues all over the place, and even my home machine using non-eskimo serves is getting DNS errors, and no updates queued for Ubuntu seem to be relevant. It is these DNS issues that are causing problems with e-mail.  I am working on resolving, I have one incoming mail server working by using external servers that do seem to be “kind of”, as in they get an error with nslookup but still return the data.  So a big mystery, if anyone knows anything that might have happened with DNS system wide, please let me know.