Keep BEGGING them to get this fixed and have your exit strategy ready. Despite so many of us complaining about this (in forums AND by contacting support through their ticket system), many of us have seen no improvement.
In my most recent interaction about this issue, the support folks have done nothing but say I'm imagining things. According to them, their spam quarantine process has not changed. Worse, I've been rudely, personally attacked and accused of doing stupid things with blacklisting addresses which caused this to happen to me and me alone. (Which I haven't done. I'm not a tech idiot so I know enough about what not to do.) Their only "help" was to tell me that since I messed it up, I need to fix it myself! Yes. SERIOUSLY! I NEED TO FIX IT MYSELF!
Trying to wade through the hundreds of spam messages each day has brought my little business to a screeching halt. But it's the rude attacks from support folks that are forcing me to leave DH. I'm appalled to be personally attacked for reporting a problem and asking them to fix it. I know it's not "just me". There's enough evidence on these forums alone (not to mention WWW-wide) about people having horrible spam problems since they switched to atmail. SHEESH!