I have been trying to tackle the problem of getting through Yahoo's spam filter for months now without luck -- hopefully you guys could give me some tips. Our service is not sending mass e-mail or anything, just Email confirmations upon registration and notification emails.
I followed all the tips from this post: http://news.ycombinator.com/item?id=92022
I have implemented RDNS lookup, SPF record, and DomainKeys/DKIM
I am able to easily get through Hotmail and Gmail's spam filters... but Yahoo is just constantly giving me a headache. I have tried everything under the sun other than calling Yahoo and scream my heads off, could anyone shed some light? Any insight would be greatly appreciated!