> ## Documentation Index
> Fetch the complete documentation index at: https://docs.commune.email/llms.txt
> Use this file to discover all available pages before exploring further.

# How do I prevent my agent's emails from landing in spam?

> DKIM/SPF/DMARC, domain warmup, bounce rates, complaint rates — what matters and how Commune handles it automatically.

## The short answer

There are two categories of deliverability problems. Authentication failures (fixable in one day). And reputation problems (takes weeks to build, minutes to destroy).

Commune handles authentication automatically. Reputation is determined by your sending behavior.

## Category 1: Authentication failures

Inbox providers check three DNS records before delivering email:

| Record | What it proves | Commune status |
| - | - | - |
| **DKIM** | This email was signed by the domain owner | Auto-configured |
| **SPF** | This server is authorized to send for this domain | Auto-configured |
| **DMARC** | What to do if DKIM/SPF fail | Auto-configured |

When you add a custom domain to Commune, all three are configured automatically. You add the DNS records, Commune verifies them, and all outbound email is DKIM-signed from that point forward.

If you're using the shared `commune.email` domain, these are already set up.

## Category 2: Reputation signals

Authentication tells providers the email is legitimate. Reputation tells them whether recipients want it.

Inbox providers look at:

| Signal | Danger threshold |
| - | - |
| Bounce rate | > 5% |
| Spam complaint rate | > 0.1% |
| Low engagement rate | \< 20% open rate consistently |
| Volume spikes | > 3x your normal daily volume |

**Bounce rate** is the percentage of emails that couldn't be delivered. High bounce rate means you're sending to bad addresses. Above 5%, Gmail and Outlook start filtering to spam.

**Complaint rate** is the percentage of recipients who click "report spam". Above 0.1% (1 in 1000) is dangerous. Above 0.3% can get your domain blocked.

## Domain warmup

New domains have no reputation. Start sending 500 emails/day from a fresh domain and every one goes to spam.

Warmup is the process of gradually establishing trust:

| Day range | Daily send limit |
| - | - |
| Days 1-3 | 50 |
| Days 4-7 | 200 |
| Days 8-11 | 1,000 |
| Days 12-14 | 5,000 |
| Day 15+ | Full volume |

**Commune handles warmup automatically.** When you create a new inbox on a new domain, the warmup schedule starts immediately. You don't configure it. If you try to send more than the current warmup limit, Commune queues the excess.

## What Commune monitors automatically

* Bounce and complaint rates per inbox (via Resend webhooks)
* Automatic suppression list (bounced addresses never receive again)
* Sending health gate: if bounce rate exceeds 5% or complaint rate exceeds 0.1%, sending is automatically paused

## Check your inbox health

```bash theme={null}
curl https://api.commune.email/v1/inboxes/INBOX_ID \
  -H "Authorization: Bearer comm_..."
```

Response includes:

```json theme={null}
{
  "data": {
    "health": {
      "bounceRate": 0.012,
      "complaintRate": 0.0004,
      "status": "healthy"
    }
  }
}
```

Status values: `healthy`, `warning` (approaching thresholds), `paused` (thresholds exceeded, sending stopped).

## The AI email fingerprint problem

LLMs produce similar patterns. "Hope this finds you well", consistent structure, similar word frequency. Inbox providers are detecting these patterns.

The fix: emails need to be genuinely wanted by recipients. Personalization helps. But the most important signal is whether people actually open and engage — that only happens if you're sending to people who opted in or have a reason to want the email.

## Related

<Columns cols={2}>
  <Card title="Delivery Monitoring" icon="chart-line" href="/features/delivery-monitoring">
    Track bounce rates, complaint rates, and inbox health metrics across all your agent inboxes.
  </Card>

  <Card title="Why Agent Emails Land in Spam" icon="newspaper" href="/blog/why-agent-emails-land-in-spam">
    Detailed technical deep-dive into deliverability signals and how to fix them.
  </Card>
</Columns>


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