How do I correct this message "blackholed by safe.dnsbl.sorbs.net"?

[SoonerBorn]

I keep getting this message "blackholed by safe.dnsbl.sorbs.net" when I try to reply to emails from my outlook. How do I correct this?"

[byron101540]

If it's legit mail, contact your server, He has a spam filter

[admin]

The "safe" SORBS aggregate list, safe.dnsbl.sorbs.net, is very comprehensive and very effective, and generates few false positives. The "unsafe" aggregate list, dnsbl.sorbs.net will block noticeably more spam, but the drawback is a significantly increased risk of false positives. SORBS also provides access to the dozen or so individual lists that make up these aggregate lists.
Link