Have had trouble with email bounced by Yahoo/xtra over the last day or so when sending via smtp.xnet.co.nz. Talked to Xtra today and the found the fault to be incorrect reverse DNS on the xnet mail server. smtp.xnet.co.nz resolves to 18.104.22.168 resolves to ananke.wxnz.net.
I spoke to Xnet CS but they didn't know when it would be fixed.
I'm writing hear to let other know about the problem and too see if anyone from Xnet can elaborate any more. It' is really important the issue gets fixed so customers can have reliable email delivery.