Deliverability problems occur when your emails fail to reach recipients' inboxes. SendOps surfaces bounce rates, complaint rates, and reputation data through the [Deliverability Reports](/reports/deliverability-reports) page so you can identify and address issues quickly. You can filter all deliverability data by channel to isolate problems to a specific sending stream.


  AWS SES enforces strict thresholds. A bounce rate above **5%** triggers a warning, and above **10%** is critical. A complaint rate above **0.08%** triggers a warning, and above **0.1%** is critical and can lead to an account review, sending pause, or permanent suspension. Monitor these metrics closely in your SendOps dashboard and take action before you reach these limits.


## Understanding bounce types

Not all bounces are equal. SES classifies bounces into two categories:

### Hard bounces (Permanent)

The recipient address is permanently invalid. Common causes:

- The email address does not exist (typo or deactivated account).
- The domain does not exist or has no MX records.
- The recipient server permanently rejected the message.

**Hard bounces count toward your SES bounce rate.** You should immediately stop sending to addresses that hard bounce. SES adds them to the account-level suppression list automatically when suppression is enabled for your channel.

### Soft bounces (Transient)

The delivery failed temporarily. Common causes:

- The recipient's mailbox is full.
- The recipient's server is temporarily unavailable.
- The message is too large.
- A connection error or timeout occurred.

SES automatically retries soft bounces for a period before giving up. Repeated soft bounces to the same address may indicate the address is effectively dead.

SendOps breaks down bounce rates into hard bounce, soft bounce, and total bounce KPIs on the [Deliverability Reports](/reports/deliverability-reports) page, along with a bounce reasons chart that shows counts by sub-type (address not found, mailbox full, content rejected, message too large, connection timeout, etc.).

## Reducing complaint rates

A complaint occurs when a recipient marks your email as spam using the "Report Spam" button in their email client. ISPs report these back to SES via feedback loops.

To keep complaint rates below the 0.1% critical threshold:

- **Include a clear unsubscribe link** in every marketing or bulk email. Make it easy to find and one-click when possible.
- **Only send to people who opted in** -- never purchase email lists or scrape addresses.
- **Set expectations at sign-up** -- tell subscribers what kind of email they will receive and how often.
- **Honor unsubscribes immediately** -- do not continue sending to people who have opted out.
- **Segment your audience** -- send relevant content to the right people rather than blasting your entire list.
- **Monitor engagement** -- if recipients are not opening your emails over several months, consider removing them from your list.

SendOps shows complaint reasons broken down by feedback type on the [Deliverability Reports](/reports/deliverability-reports) page, so you can see whether complaints are primarily "abuse", "not-spam", or other categories.


  SES maintains an account-level suppression list that automatically prevents sending to addresses that have previously hard bounced or complained. SendOps shows and manages this suppression list directly on the [Deliverability Reports](/reports/deliverability-reports) page -- you can search, sort, and delete entries without going to the AWS Console. Each channel's suppression behavior is controlled by its **Suppression Reasons** setting, which can be set to suppress on bounces only, bounces and complaints, or disabled entirely.


## Configuring deliverability notifications

SendOps can alert you when deliverability metrics cross thresholds. Under [Configuring Notifications](/notifications/configuring-notifications), the **Deliverability** category includes:

- **Bounce Rate Threshold** -- triggered when bounce rate exceeds a configured percentage. Default threshold is 5%.
- **Complaint Rate Threshold** -- triggered when complaint rate exceeds a configured percentage. Default threshold is 0.1%.
- **Bounce Rate Trend** -- alerts on a sustained upward trend in bounce rates.
- **Complaint Rate Trend** -- alerts on a sustained upward trend in complaint rates.
- **Blocklist Detection** -- triggered when a sending IP or domain is detected on a blocklist.
- **Suppression List Growth Spike** -- alerts when the suppression list grows unusually fast.

For bounce and complaint rate thresholds, account admins can set **per-channel threshold overrides** so that channels with different risk profiles (for example, marketing vs. transactional) can have different alert thresholds. Notifications are delivered via in-app alerts and email by default.

## Responding to an SES account review

If your bounce or complaint rates exceed thresholds, AWS may place your SES account under review. During a review:

1. **You can still send email**, but AWS is watching your metrics closely.
2. You receive an email from AWS with the subject "Amazon SES Sending Review" explaining the issue.
3. You typically have **a limited window** (often 24-48 hours) to improve your metrics before AWS may pause your sending.

**Steps to respond:**

1. Immediately identify the source of bounces or complaints in your SendOps [Deliverability Reports](/reports/deliverability-reports). Filter by channel and date range to find the spike.
2. Check the ISP breakdown table to see if the problem is concentrated at a specific mailbox provider.
3. Stop any campaign or sending flow that is generating the problem.
4. Clean your recipient lists -- remove invalid addresses, unengaged recipients, and anyone who has complained.
5. Reply to the AWS review notification with a summary of what caused the issue and what you have done to fix it.
6. Monitor your rates in SendOps over the following days to confirm improvement. The reputation score on the Deliverability Reports page shows your current standing.

If AWS pauses your sending, you will need to submit a case through AWS Support to have it reinstated.

## IP reputation and shared vs. dedicated IPs

By default, SES sends email from a pool of **shared IP addresses** managed by AWS. Your reputation is tied to the overall health of that shared pool plus your own sending behavior (domain reputation).

If you send high volumes (over 100,000 emails per day), consider **dedicated IPs** in SES:

- **Pros** -- your reputation is entirely under your control; no other senders can affect it.
- **Cons** -- you must warm up new IPs gradually, and low-volume senders may see worse deliverability than the shared pool.

Dedicated IPs are configured in the AWS SES Console. SendOps monitors deliverability regardless of whether you use shared or dedicated IPs.

## Authentication issues (DKIM, SPF, DMARC)

Failed authentication is a leading cause of emails landing in spam or being rejected outright. Check these in order:

1. **DKIM** -- ensure all three DKIM CNAME records are published and resolving correctly. See [Domain Verification](/troubleshooting/domain-verification) for detailed checks.
2. **SPF** -- your SPF record must include `include:amazonses.com`. If you use a custom MAIL FROM domain, the SPF record goes on that subdomain.
3. **DMARC** -- verify your DMARC record at `_dmarc.yourdomain.com`. Start with `p=none` to monitor before enforcing.

You can verify domain authentication status on the [Email Identities](/domains/email-identities) page in SendOps, which shows DKIM verification state for each domain.

## Common deliverability checklist

Use this checklist when investigating deliverability drops:

- [ ] Bounce rate is below 5% (warning) / 10% (critical) in [Deliverability Reports](/reports/deliverability-reports)
- [ ] Complaint rate is below 0.08% (warning) / 0.1% (critical)
- [ ] DKIM is passing (all three CNAME records resolving)
- [ ] SPF is passing (`include:amazonses.com` in SPF record)
- [ ] DMARC record exists and alignment is passing
- [ ] SES account is not in sandbox mode (see [SES Sandbox & Production](/sending-email/ses-sandbox))
- [ ] Sending to opted-in recipients only
- [ ] Unsubscribe link is present and functional
- [ ] Channel suppression reasons are configured appropriately (bounces only, or bounces and complaints)
- [ ] No recent changes to DNS records or sending infrastructure
- [ ] Deliverability notifications are enabled so you are alerted to threshold breaches

## What's next?

- Review your current metrics in [Deliverability Reports](/reports/deliverability-reports).
- Check [Engagement Metrics](/reports/engagement-metrics) to understand open and click rates.
- Set up [deliverability notifications](/notifications/configuring-notifications) to get alerted before thresholds are breached.
- For DNS and authentication troubleshooting, see [Domain Verification](/troubleshooting/domain-verification).