Now I notice that the mailserver penalty applied to that domain has crept onto my other domains as well. Now even my regular business correspondences, as in 1 to 1 emails from these non-spam domains, fall into spam folders.
Is there any solution? How do I distance myself from the bad domain, and fix the problem?
I'm also thinking of using something like Google Apps, I'm not sure exactly how it works but used to know someone who used it for his business email. I assume it benefits deliverability in some way.