DMARC report lists ten sending IPs, I can't tell which are ours
Per-source breakdowns in DMARC reports map each IP to a service. That surfaces shadow IT sending in your name.
Try this first
- 1Use a DMARC aggregator (dmarcian, Postmark) to visualise reports
- 2Look up the PTR record per IP, that usually reveals the provider
- 3Match IPs to your known services (CRM, ESP, ticketing)
- 4Unknown sources: block or bring under DKIM/SPF
When to bring us in
If you can't trace an IP, don't jump to p=reject, identify first.
See also
- Our emails land in spam for some recipientsAlmost always an SPF, DKIM, or DMARC setting that is wrong or missing, or a sender name that mimics a well-known brand.
- Someone reports receiving phishing emails "from us"Read: spoofing. Someone is abusing your sender name, not necessarily your actual mailbox.
- An email bounces (NDR): delivery failedThe NDR text usually states the exact reason. Reading it is step one.
None of the above fits?
Describe your situation below. We pass your input plus the steps you already saw to our AI and return tailored next-step advice. If it's too risky to DIY, we'll say so.
Or skip the DIY entirely
Our Managed IT clients do not look these things up. One point of contact, a fixed monthly price, resolved within working hours.