Blacklisted

Blacklisted

Hello,

i just got this reply from a partner

INVALID_ADDRESS, ERROR_CODE :554, ERROR_CODE :5.7.1 Service unavailable; Client host [135.84.80.217] blocked using dnsbl.sorbs.net; Currently Sending Spam See: http://www.sorbs.net/lookup.shtml?135.84.80.217


What can i do to be not on the black list?

thanks,

Robert