I am using SMF v 2.0 and I noticed all those who registered on my forum with a yahoo ID never received their log-in information. I also tried registering with a yahoo ID and I experienced the same problem. I have never received my log-in information in my yahoo in-box or the my spam box up to this day. Can anyone please help me with this problem?
As far as I can remember, yahoo always checks for SPF records and if PTR (reverse DNS) matches.
I'm not sure who your host is, but it might very well be worth checking it out.
My host name is siteground, but I am going to do as you said.
Let us know when you've heard back from siteground :)