52.222.186.101
server-52-222-186-101.ham50.r.cloudfront.net
52.222.186.115
server-52-222-186-115.ham50.r.cloudfront.net
52.222.186.21
server-52-222-186-21.ham50.r.cloudfront.net
52.222.186.48
server-52-222-186-48.ham50.r.cloudfront.net

eu-smtp-inbound-1.mimecast.com.
eu-smtp-inbound-2.mimecast.com.