Error Message
I am analyzing two transactional emails sent by the InfinityFree ecosystem related to account suspension due to inactivity.
Both emails pass SPF, DKIM, and DMARC authentication; however, they show different delivery outcomes in Gmail.
Email A (Inbox)
Subject:
if0_*****.infinityfree… (Website for *****.rf.gd) is suspended for inactivity!
Sent via Amazon SES (eu-west-1)
Domain: infinityfree…
IP: 54.240.3.19
Delivered to Inbox
Email B (Spam)
Subject:
InfinityFree.com account: q*****.infinityfree.com Inactive
Sent via ByetCluster infrastructure (byetcluster…)
Sender domain: hostmessage.info
IP: 82.163.176.4
DMARC policy: quarantine
Delivered to Spam folder
Includes internal system identifiers (account manager ID / account ID)
Contains a reactivation link (HTTP with query parameters)
Technical observations:
Both messages pass SPF, DKIM, and DMARC authentication
Email A uses Amazon SES with consistent domain alignment (infinityfree.com)
Email B uses a ByetCluster relay with intermediate domain (hostmessage.info)
Clear difference in sending infrastructure reputation (SES vs shared SMTP cluster)