some Users are unable to send E-mails to us.
They are getting
Remote Server returned '554 5.0.0 <utm.acme.at #5.0.0 smtp; 550 Error: open resolver; https://www.spamhaus.org/returnc/pub/220.127.116.11>'
if I klick on the Link Spamhaus tells me that the Problem is on the receiving side.
I do'nt know where the IP is from.
I've read the Spamhaus Page but can't figure out what's wrong.
The Count of Emails getting blocked are rising every day and i have to solve the problem.
I've googled the problem but there are no evidences :-(
would be lucky if someone could help
seems you can't use spamhaus RBL from public / open DNS-resolvers.
Disable the RBL or try a provider-DNS.
"Queries cannot successfully be made to…