How to integrate monitoring with security incident response?

Picture this: your DMARC reports start showing authentication failures from IP addresses you've never seen before. Your complaint rate jumps overnight. Volume from your domain spikes without any scheduled campaign. Any one of these could mean your domain is being spoofed or your sending infrastructure has been compromised. That's not a deliverability problem. That's a security incident.

The trouble is most email teams and security teams operate in separate silos. Email monitors bounce rates. Security monitors network logs. Nobody connects the dots until the damage is done. Here's how to bridge that gap with a practical workflow.

Step 1: Define your alert triggers

Start by agreeing on which email signals should automatically page your security team, not just your email team. Good candidates include:

• DMARC authentication failures from unknown IPs. This can mean someone is spoofing your domain
• Complaint rate spike above your normal baseline. Anything more than double your trailing 30-day average deserves a look
• Unexpected sending volume from your domain. If you sent no campaigns today but DMARC shows 10,000 messages leaving under your name, investigate immediately
• New DKIM selectors appearing in DMARC reports that you didn't create. A sign of unauthorized sending infrastructure
• Sudden blocklist appearance, especially on reputation-sensitive lists like Spamhaus

Step 2: Route the right alerts to the right people

Not every alert needs a security response. A bounce rate spike from a bad list segment is an email problem. Authentication failures from unknown infrastructure is a security problem. Write that distinction down somewhere your team can find it (a shared runbook, a Notion page, a printed cheat sheet on the wall if that's what works).

Create a direct channel between your email team and your security team. This could be a dedicated Slack channel, a shared inbox, or a ticket tag. The format matters less than the habit. When your email team spots something that fits the security criteria, they need a fast, frictionless way to flag it.

Step 3: Run a basic investigation workflow

When an alert fires, here's a repeatable starting sequence:

1. Pull your DMARC report for the flagged timeframe. Identify which sending sources passed and which failed. Look for IP ranges you don't own.
2. Cross-reference against your authorized sending infrastructure. If the IP isn't in your SPF record and wasn't sent by your ESP, treat it as suspicious.
3. Check blocklists. If you're newly listed, find out which list and read the reason. That often tells you what type of abuse was detected.
4. Review account access logs for your ESP and domain registrar. Unauthorized logins or API key usage can confirm a compromise.
5. Contain first, investigate second. If you suspect your ESP account or sending domain is compromised, rotate API keys and credentials before spending hours in logs.

Step 4: Document as you go

Now your compliance and legal teams will thank you later. Every security-related email incident should have a written timeline: when the anomaly was detected, what signals triggered the alert, what actions were taken, and what the outcome was. This is also useful if a mailbox provider or compliance investigation ever asks for your incident history.

What this looks like in practice

Say your DMARC reports start showing 5,000 daily failures from an IP block in a region you don't operate in. Your email team spots it Monday morning. They drop a note in the shared security channel with the IP range and a screenshot of the DMARC data. Security checks the IP against known threat intelligence feeds, confirms it's associated with a phishing campaign, and files a report with the relevant registrar or hosting provider. Your email team tightens your DMARC policy to reject rather than quarantine. The whole loop closes in hours instead of days.

That's the goal. Not a complex integration project. Just a clear, practiced handoff between two teams who both care about keeping your domain safe.

If you're not sure whether your DMARC setup would even catch unauthorized senders, you can check your DMARC record right now with our free DMARC parser. Or if something looks broken already, our SOS hotline is free and we actually pick up.