Amazon SES Spam: Diagnose, Fix & Prevent Inbox Placement Issues

Amazon Simple Email Service (Amazon SES) offers a powerful and reliable platform for sending emails at scale. However, while it ensures strong deliverability performance, it doesn’t natively show where your messages land, whether in the inbox, promotions tab, or spam folder.

SES gives you deliverability signals, but it cannot show inbox placement at the provider level. No sending platform can because mailbox providers do not expose that data. Without that visibility, teams cannot confirm whether issues come from authentication, reputation, or engagement patterns until performance drops.

For teams using Amazon SES for cold outreach, marketing, or transactional campaigns, understanding these blind spots is essential to maintaining trust with mailbox providers and maximizing engagement.

This guide walks you through how to identify and resolve spam placement issues in Amazon SES, strengthen your authentication and reputation, and monitor inbox performance effectively so your emails consistently reach the right audience.

How to Diagnose Amazon SES Spam Issues

Email content plays a significant role in deliverability for any provider, including SES. When links, tracking paths, formatting, or template structure look risky to mailbox providers, messages can be filtered even if authentication is correct. Reputation and sending setup still matter, but content issues can independently trigger filtering and should be evaluated early in the diagnosis process.

Segment your email campaigns

Separate transactional emails from outreach activity. Mixing both under a single SES identity contaminates engagement metrics. Transactional messages typically receive opens and clicks, while cold outreach usually does not. When mailbox providers observe uneven engagement across identical headers and sender metadata, they flag the inconsistency and downgrade trust.

Determine the scope of the issue

Verify whether the issue is domain-wide or limited to a single configuration set. If every subdomain is being placed in spam, you’re likely facing a reputation-level problem. If only one SES identity or sending region is affected, the issue likely stems from DNS settings or IP allocation.

Collect real evidence

Skip spam-score tools. Run an Inbox Placement Test to see exactly where your emails land, such as Gmail inbox, Outlook spam, or elsewhere. Document the placement results and compare them with authentication alignment, complaint rates, and bounce logs.

Run key technical checks

Verify SPF, DKIM, and DMARC alignment (ensure SPF and DKIM align with your visible From domain, and DMARC policy is in place). Check for forwarding loops, mismatched envelope (MAIL FROM) domains, or expired TLS certificates. These small faults compound and gradually damage sender reputation .

Step-by-Step Guide to Fix Amazon SES Spam Issues

Once you’ve identified that your emails are landing in spam, the next step is to fix the technical and behavioral causes behind it. Amazon Simple Email Service (Amazon SES) delivers messages efficiently, but it doesn’t manage authentication, reputation, or engagement signals.

The recovery process follows a clear sequence. You start by correcting DNS records, then rebuild sender reputation, restore engagement, and monitor deliverability over time. Each step addresses one layer of trust that mailbox providers evaluate before placing your emails in the inbox.

Follow the steps below in order to restore domain reputation and maintain consistent inbox placement.

Step 1: How to fix SPF, DKIM, and DMARC issues in Amazon SES

Many SES senders encounter the same issue: authentication records that look correct in DNS but fail alignment checks. SPF, DKIM, DMARC, envelope (MAIL FROM), and rDNS (Reverse DNS) must all be configured correctly for mailbox providers to trust your domain. If one element is incorrect, all messages will inherit the resulting degraded reputation.

1. Configure SPF for SES identities

SPF is the first line of defense for authentication. Each verified SES identity needs an SPF record that explicitly authorizes Amazon Simple Email Service (Amazon SES). In Route 53 or your external DNS, include the following record:

v=spf1 include:amazonses.com -all

The DNS lookup limit for SPF is ten. Exceeding this limit breaks SPF resolution and effectively invalidates the record. Many teams chain multiple SaaS tools (Salesforce, HubSpot, Amazon SES) and unknowingly exceed the limit. Remove redundant include: statements, and, if necessary, consider SPF-flattening tools but be aware of their trade-offs (increased DNS size and maintenance overhead).

2. Enable easy DKIM

SES offers Easy DKIM, but it only works if your DKIM signing domain (d=) aligns with your visible From: domain or subdomain. For example, if your From: address is user@news.yourdomain.com but SES signs the message with a DKIM domain of amazonses.com, DMARC will fail because the DKIM signing domain does not align with the visible From domain,even if DKIM verification passes. Use custom DKIM keys for each domain rather than sharing keys across environments. Regenerate keys whenever you migrate regions, since SES DKIM keys are region-specific.

3. Configure DMARC policies correctly

DMARC requires that either SPF or DKIM (or both) align with the “from” domain. Start with a relaxed policy to collect data:

v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com

Once alignment checks pass consistently, increase enforcement in stages to:

p=quarantine

then finally:

p=reject

These escalation steps signal to mailbox providers that you actively monitor and mitigate abuse and spoofing. Consistent reporting builds domain trust more effectively than content tweaks.

4. Use a custom mail-from domain

By default, Amazon Simple Email Service (Amazon SES) uses shared return-path domains under Amazon’s infrastructure. Shared Return-Path domains provide a weaker trust signal for mailbox providers. Configure a custom MAIL FROM domain on your root domain (for example, bounce.yourdomain.com). Verify the MAIL FROM in Amazon SES, and ensure your SPF includes the MAIL FROM domain and your DMARC policy accommodates it. This step ensures that bounce handling and complaint feedback loop data flow back to your domain rather than Amazon’s.

5. Match rDNS and HELO

Mailbox providers compare the reverse DNS for your sending IP with your declared HELO/EHLO host. Both should resolve to the same name (or to the mail-from domain). Amazon Simple Email Service (Amazon SES) handles most of this automatically. If you use dedicated IPs, verify that rDNS is configured correctly for the region. Misaligned rDNS looks identical to spoofing to Gmail’s filters.

Step 2: Rebuild sender reputation and infrastructure

Fixing authentication stops immediate damage. Rebuilding reputation prevents long-term spam placement. Restoring domain trust requires a sequence of measurable signals, not a single action. Focus on predictable, genuine engagement and technical discipline. Trust is rebuilt through consistent behavior over several weeks.

1. Stop sending cold traffic immediately

Once you’re flagged, each new send reinforces the negative signal. Mailbox providers treat high volume from a flagged domain as evidence of spammy send behavior

What to do first:

• Pause all cold campaigns for at least 72 hours.
• Keep only transactional or product notifications active if their open rates exceed  30% .
• Monitor complaint and bounce rates daily using Amazon Simple Email Service (Amazon SES) reputation metrics.

Many senders continue running campaigns, assuming the issue will resolve on its own. It doesn’t. SES reputation is domain-wide, not campaign-specific, and every message inherits the same penalty.

2. Diagnose before rebuilding

Don’t guess why you’re in spam. Confirm it. Start by running a full Inbox Placement Test to identify which mailbox providers are filtering your messages.

• In many cases Gmail shows filtering signals first, followed by Outlook and Yahoo. Gmail’s filtering systems react quickly to negative engagement patterns.
• If only Gmail marks your messages as spam, the issue is behavioral, tied to engagement and volume patterns.
• If all providers mark your messages as spam, the problem is systemic and indicates compromised domain trust.

Run the test at least twice, one week apart. Compare placement results to measure recovery. Reputation doesn’t shift overnight, expect stabilization over 10–14 days.

3. Rebuild engagement through controlled warmup

Reputation recovers through positive interactions rather than through raw volume. Use MailReach Email Warmup to support that process when your activity targets B2B inboxes.

• Start a 14-day warmup cycle per domain or mailbox.
• Begin with 30-40 emails/day, increasing by 20 per day.
• Run warmup in parallel with low-risk live sends to dilute negative engagement signals
• Check placement reports every three days to confirm improvement.

Mailbox algorithms reward predictability. When your domain shows steady engagement, including opens, replies, and message recoveries, filters adjust their trust thresholds.

4. Clean your database and stop sending to inactive or invalid contacts

Every invalid address reinforces the mailbox provider’s spam suspicion. Mailbox providers interpret repeated bounces and zero engagement as indicators of poor sender reputation. Follow the checklist below for recovery data hygiene.

• Remove bounced and role-based addresses.
• Validate all new leads before import.
• Stop mailing contacts that haven’t opened your emails in 60 days.
• Keep bounces under 2% and spam complaint rates under 0.3% in Postmaster Tools.

With clean data, moderate, genuine engagement will improve domain reputation more quickly than warmup alone. For a broader hygiene process, see our Deliverability Checklist.

5. Scale up volume gradually

Once your inbox placement starts improving, scale sending volume gradually. Deliverability collapses when senders ramp too fast. SES tracks sending velocity, and Gmail monitors daily changes in engagement..

Safe recovery pacing:

• Day 1-2 - 30–50/day
• Increase by ~20/day
• Max 80–100/day for B2B outreach
• Do not exceed 100/day during recovery

Watch reply rates and spam reports. If reply rates dip or spam reports increase, pause or slow your ramp-up because filters may be re-evaluating your domain.

Step 3: Strengthen technical message structure

Even when your authentication and reputation look perfect, Gmail can still send your message to spam because your message appears inconsistent. Mailbox filters don’t care how clever your copy is. They evaluate the message components, including the headers, tracking paths, encoding, and formatting.

Required headers

Message headers contain the core identity signals for the message. SES generates some headers automatically, but not always in ways that align with your domain. Every header should confirm the same identity.

If you send from sales@yourdomain.com, your Return-Path (MAIL FROM) should use a custom subdomain such as bounce.yourdomain.com, not Amazon’s shared return-path domain.

Reserve “List-Unsubscribe” headers for marketing sends. Adding that header to transactional emails (for example, password resets) can cause messages to be classified as marketing or spam because it blurs intent.

Link & tracking hygiene

Before recipients click, mailbox providers examine links and tracking domains to assess message authenticity

If your visible link (yourdomain.com) doesn’t match the redirect target (crmvendor.net), that single mismatch is enough to flag the message as suspicious.

Use a tracking subdomain such as track.yourdomain.com. Keep redirect chains short, ideally a single redirect hop and avoid public shorteners such as bit.ly.

Preference center

Most filters track user interaction data over time. When recipients repeatedly use “Report Spam” instead of “Unsubscribe,” that negative feedback is attributed to your domain reputation.

The remedy is to provide recipients with a frictionless unsubscribe experience

Host your preference center on your primary domain rather than on a CRM’s generic page. Integrate it with your CRM or outreach tool and synchronize opt-outs immediately. 

Step 4: Make deliverability observable and proactive

Amazon Simple Email Service (Amazon SES) gives you data, but not insight. Most senders only realize they’re in trouble after inbox placement drops or suspension warnings appear. That’s reactive. Operators who act proactively monitor deliverability in real time rather than after damage occurs.

SES’s Virtual Deliverability Manager (VDM) changes that. It surfaces bounces, complaints, and engagement signals via  event streams you can act on immediately. 

VDM reports what events occurred, but not how different mailbox providers classified those messages. To determine inbox vs. spam placement by provider, run MailReach’s Inbox Placement Test.

1. Enable VDM

VDM provides Amazon Simple Email Service (Amazon SES) with near-real-time deliverability data, including engagement trends, bounces, and complaint signals. VDM is disabled by default.

To enable it:

1. In the AWS console, go to SES → Configuration Sets.
2. Select your active configuration set.
3. Under VDM Options, activate both “Deliverability Dashboard” and “Engagement Tracking.”

This setup unlocks near real-time event data through Amazon SNS (Simple Notification Service) and lets your team detect spikes in negative signals before they affect sender reputation.

2. Create event destinations

SES uses Event Destinations to push deliverability events such as bounces, complaints, and delivery failures into external systems, turning raw activity into actionable alerts.

To configure them:

• Go to SES → Configuration Sets → Event Destinations and select SNS as the destination type. 
• From there, choose the event categories you want to capture, starting with bounces, complaints, and delivery failures, since these directly affect reputation. 
• Connect the SNS topic to your alerting channel, whether that’s Slack, email, or your internal monitoring system.

Once configured, Event Destinations provide near-real-time visibility into deliverability. Your team no longer needs to wait for periodic reputation reports; alerts arrive within minutes of a bounce or complaint spike, giving you time to act before thresholds are breached and mailbox providers degrade sender trust.

3. Set CloudWatch alarms

CloudWatch is your early warning system for reputation health. Once Event Destinations are configured, it collects SES metrics such as bounces, complaints, and engagement signals from VDM. The goal is to detect deliverability changes before mailbox filters penalize your domain.

To configure it, go to CloudWatch → Alarms → Create Alarm, and select SES Metrics. Choose either Reputation.BounceRate or Reputation.ComplaintRate depending on what you want to track. Next, define your trigger thresholds and choose how alerts should be sent, typically through SNS or email.

Once alarms are configured, CloudWatch begins monitoring in real time. The moment one of these thresholds is crossed, you’ll receive an immediate alert. That visibility enables your team to act before mailbox providers degrade sender reputation

Step 5: Warm up your SES domains and IPs gradually

Warm-up is not optional; it’s how you demonstrate reliability after fixing authentication and configuration. Amazon Simple Email Service (Amazon SES) can deliver at scale, but it doesn’t provide a dedicated inbox network; MailReach offers that capability for B2B/professional emails.

MailReach warm-up operates through trusted Google Workspace and Microsoft 365 inboxes, simulating genuine human interactions that build domain-level trust with Gmail and Outlook. SES users should warm up domains, not IPs, because reputation belongs to your sending identity rather than Amazon’s shared infrastructure.

Warm-up doesn’t repair poor data quality or correct broken DNS records. It strengthens deliverability signals once authentication and data hygiene are in place.. The goal is consistent engagement, not volume.

Ramp strategy

A warm-up should increase volume methodically. A sudden jump from zero to bulk sending signals spam-like behavior, even with a correct configuration. The framework below follows MailReach’s recommended sending thresholds for a 14-day recovery window.

Each step relies on engagement signals like opens, replies, and message recoveries (for example, messages moved from spam to the inbox) within MailReach’s peer-to-peer network. This activity signals to mailbox providers that your domain behaves like a legitimate sender

ISP-aware gradients

Gmail often shows the quickest response to engagement changes, while Outlook places more weight on long-term reputation history. Favor a slightly higher share of early sends to Gmail to accelerate trust, then expand evenly across providers. Avoid sudden cross-provider jumps; each ISP evaluates sender consistency within its own ecosystem..

Using MailReach to boost trust

MailReach connects SES senders to a controlled inbox network where messages receive opens, replies, and, when appropriate, classification as not spam. This restores positive interaction signals that SES alone may not generate.

Keep the warm-up active even after messages begin reaching inboxes to maintain steady reputation growth. Combine this with ongoing monitoring via MailReach’s Inbox Placement Test and Warm-Up API to validate progress across Gmail, Outlook, and Yahoo.

How to Prevent Amazon SES Spam Issues

You can fix deliverability once, but keeping it stable requires discipline. Amazon Simple Email Service (Amazon SES) provides sending infrastructure, not a deliverability safety net. When your messages begin reaching inboxes again, your focus should shift from recovery to consistency. The goal is to prevent the gradual decline that starts once monitoring stops.

Monitor inbox placement weekly

Monitoring inbox placement provides an early warning. For example, small shifts often appear days before major deliverability drops. Run a MailReach Inbox Placement Test every week to track long-term placement trends across Gmail, Outlook, and Yahoo.

Key signals to watch:

• A Gmail inbox rate below 80% indicates engagement decay
• Rising spam placement in Outlook suggests domain inconsistency or negative reputation feedback.
• Yahoo inbox volatility often lags Gmail’s behavioral trends by several days.

Avoid reacting to a single test. Track changes over multiple weeks to confirm patterns. Stability, not spikes, defines a healthy sender reputation

Control bounce and complaint thresholds

Deliverability failures rarely occur overnight. They result from gradual increases in bounces and complaints. The key is identifying these shifts before mailbox filters take corrective action.

Use Amazon Simple Email Service (Amazon SES) reputation metrics to track bounce and complaint rates on a daily basis. If either metric trends upward for three consecutive days, pause outbound sending immediately. Don’t wait until inbox placement deteriorates further

How to act on thresholds:

• If the bounce rate exceeds 2%, audit your lead sources and suppression logic.
  If the complaint rate exceeds 3%, review email frequency, targeting accuracy, and unsubscribe visibility.
• Investigate anomalies and outliers rather than aggregated averages. A single campaign spike can depress domain reputation for several weeks.

Mailbox filters treat each bounce or complaint as evidence of poor sender reliability. Preventive monitoring keeps your sender reputation stable and predictable.

Remove risky or inactive addresses

Data decay is a silent spam trigger. Stale or unverified addresses gradually degrade engagement metrics, even when core lists appear clean.

• Identify unengaged addresses early (for example, no opens or replies in 30–60 days).
• Remove role-based or system emails (for example, postmaster@, info@) that never engage.
• Run monthly validation cycles using an email verification API.
• Watch for sudden drops in engagement from new lists. This often signals that purchased or scraped data has entered your funnel.

Operationalize Your SES Deliverability

 Maintaining inbox placement is an ongoing process. Once authentication, engagement, and reputation are stable, the goal is to keep every system in sync and every signal consistent.

Teams that succeed with Amazon Simple Email Service (Amazon SES) treat deliverability as a measurable operation, not a one-time recovery task. They monitor inbox placement regularly, keep lists clean, and respond to early warning signs before filters act. Over time, this consistency builds lasting trust with mailbox providers.

MailReach helps teams maintain that consistency. It runs inbox placement tests, simulates authentic engagement, and tracks domain reputation in real time. These insights make it easier to prevent reputation loss and sustain inbox placement across Gmail, Outlook, and other providers.

Begin your 14-day warm-up and inbox placement test with MailReach to keep every send trusted and inbox-ready.