Which IP actually sent your email?
The final SMTP connection into Siglumo identifies the peer that delivered the tested copy. A domain lookup can return other mail-related or website-hosting addresses; it does not prove that this particular message used them.
Read the evidence in separate groups
- Observed sending IP: recorded by Siglumo’s receiving connection.
- Other domain sending addresses: reported by the lookup, without proof this message used them.
- Hosting infrastructure: website or other non-mailing addresses, with their own context.
Shared sending and historical subjects
Historical incident reports and example subjects describe the address history returned by a service. They do not identify the account responsible. On shared infrastructure, activity may belong to other senders. A different subject is a comparison result, not proof of who sent a historical message.
If a lookup labels the observed peer as a web host, the recorded delivery connection still establishes its role in this email. Keep that provider classification as a source discrepancy.
Send directly for a useful test
Forwarding creates a new send. Its observed connection describes the forwarding account, not necessarily the original marketer’s infrastructure. Send directly from the intended campaign tool when checking that setup.