A listing in DroneBL is NOT always related to spam. But in most cases because of an open proxy !!!
Details about 177.21.236.1
Country: Brazil (BR)
Reverse: ip-177-21-236-1.novafibratelecom.com.br
Autonomous System Number: AS11835
Lookup results for 177.21.236.1
No specific incidents regarding 177.21.236.1 were found in DroneBL's incident tracking system. This means that your IP is not listed in DroneBL.