Please check the popular BL sites for testing your connection, e.g.:

SENDERBASE.ORG

SORBS.NET (dnsbl.sorbs.net)

SPAMHAUSE.ORG (sbl.spamhaus.org, xbl.spamhaus.org, pbl.spamhaus.org --> ZEN.spamhaus.org)

MULTIRBL.VALLLI.ORG or SPAMCOP.NET

If you are a mail server admin - you can check your SMTP server config ...

(e.g.: TLS/SSL conf, open relay gaps, DNS/rDNS - DNS MX records, accepting connection on 25 tcp port from Internet, SPF)




Also you can contact with us via your alternate e-mail address: postmaster@ukw.edu.pl, or use this web contact form