When sending emails through Amazon SES, Gmail often appends a "via amazonses.com" label to the sender information. This occurs when Gmail detects that the email is being relayed through a third-party service, even if the email is properly authenticated with SPF and DKIM.

Gmail implements this feature to help users identify potentially suspicious emails. According to Google's documentation:

"Gmail checks whether emails are correctly authenticated. If your messages are sent by a bulk mailing vendor or by third-party affiliates, please publish an SPF record that includes the IPs of the vendor or affiliates which send your messages and sign your messages with a DKIM signature that is associated with your domain."

First, ensure your email authentication is properly configured:

// Example SPF record for your DNS (TXT record):
"v=spf1 include:amazonses.com ~all"

// Example DKIM setup in Amazon SES:
1. Go to SES → Domains → Verify a New Domain
2. Generate DKIM settings
3. Add the CNAME records to your DNS

To completely remove the "via" tag, you need to meet these requirements:

• Use your own domain in the "From" address (not an @amazonses.com address)
• Have both SPF and DKIM properly configured and passing
• Ensure your domain alignment matches (DMARC policy)

Adding a DMARC record can help establish full domain alignment:

// Example DMARC DNS record (TXT record for _dmarc.yourdomain.com):
"v=DMARC1; p=none; rua=mailto:youremail@yourdomain.com"

If you're still seeing the "via" label after implementing these measures:

1. Verify all DNS records using tools like MXToolbox or Google Admin Toolbox
2. Check your email headers for any authentication failures
3. Ensure you're using the same domain in From, Return-Path, and DKIM

For programmatic sending, ensure your SDK configuration includes proper identity settings:

// Example Node.js SES v3 SDK configuration
const { SESClient, SendEmailCommand } = require("@aws-sdk/client-ses");

const client = new SESClient({ region: "us-east-1" });

const params = {
  Source: "sender@yourdomain.com", // Must match verified domain
  Destination: { ToAddresses: ["recipient@gmail.com"] },
  Message: {
    Subject: { Data: "Test email" },
    Body: { Text: { Data: "This is a test email" } }
  }
};

const command = new SendEmailCommand(params);

Many developers using Amazon SES notice that Gmail displays a "sent via amazonses.com" label even after implementing SPF and DKIM authentication. This occurs when Gmail detects the email originated from a third-party service rather than directly from your domain.

While SPF and DKIM are essential, Gmail's algorithm looks for additional signals of domain alignment:

• DMARC policy (even in monitoring mode)
• From: header domain matching DKIM signing domain
• Consistent envelope sender and header sender

Here's a full configuration example that removes the "via" indicator:

# SPF Record (DNS TXT)
"v=spf1 include:amazonses.com ~all"

# DKIM Setup (SES Console)
1. Verify your domain in SES
2. Generate DKIM records in SES console
3. Add CNAME records to your DNS:

# Example DKIM records
Host: k1._domainkey.example.com
Value: k1.dkim.amazonses.com

# DMARC Record (Recommended)
"v=DMARC1; p=none; rua=mailto:dmarc-reports@example.com"

For AWS SDK users, ensure proper header configuration:

const params = {
  Source: '"Sender Name" ',
  Destination: { ToAddresses: [recipient] },
  Message: {
    Body: { /* ... */ },
    Subject: { Data: "Test Email" }
  },
  // Critical for domain alignment
  ConfigurationSetName: "your-config-set"
};

• Verify DNS records with dig or online tools
• Check raw email headers for authentication results
• Ensure FROM address uses your verified domain
• Test with different email clients to isolate Gmail-specific behavior

If the issue persists after 48 hours of DNS propagation:

1. Contact AWS Support with full email headers
2. Submit feedback to Gmail through the "Report phishing" dropdown
3. Consider using SES's domain verification feature