This company VerticalResponse Inc doesn't care about spam abuse and will keep blasting you with unwanted mail while ignoring abuse complaints. I suggest you nullroute their network.
NetRange: 184.108.40.206 - 220.127.116.11 CIDR: 18.104.22.168/22 NetName: VERTICALRESPONSE
They also spam you out of this range too:
NetRange: 22.214.171.124 - 126.96.36.199 CIDR: 188.8.131.52/22 NetName: MEGA-9 NetHandle: NET-216-55-172-0-1 Parent: NET216 (NET-216-0-0-0-0) NetType: Direct Allocation OriginAS: AS30447 Organization: InternetNamesForBusiness.com (INFB) NetRange: 184.108.40.206 - 220.127.116.11 CIDR: 18.104.22.168/19 NetName: MEGA-6 NetHandle: NET-209-235-128-0-1 Parent: NET209 (NET-209-0-0-0-0) NetType: Direct Allocation OriginAS: Organization: InternetNamesForBusiness.com (INFB) RegDate: 2006-09-28 Updated: 2012-02-24 Ref: https://whois.arin.net/rest/net/NET-209-235-128-0-1
So nullroute 22.214.171.124/22, 126.96.36.199/22 and 188.8.131.52/19 to protect your e-mail inboxes from VerticalResponse spam.
Also if you forward the spam they send you to their abuse system, it rejects it because it has "spam like characteristics":
[email protected] SMTP error from remote mail server after end of data: host mx1.megamailservers.com [184.108.40.206]: 550 5.7.1 w6GJWVT5024637 This message has been blocked for containing SPAM-like characteristics.