Gmail delivery help

Fix Gmail delivery failures by configuring email authentication, monitoring sender reputation, and following Google's sender guidelines.

This topic covers Gmail-specific delivery requirements and remediation steps. For Google's full sender guidelines, see Email sender guidelines.

Why Gmail delivery fails

Delivery failures usually result from one or more of the following:

• Sending too many emails.

• A sudden increase in the number of emails sent.

• Sending emails to spam trap addresses.

• Sending emails to invalid addresses.

• The sending IP address is on a blocklist.

• Emails are reported or marked as spam by Gmail users.

• Using a new IP address to send emails without a warm-up period.

• Incomplete or incorrect DNS records for the domain name.

• Failed email authentication.

• Emails contain certain attachment types or links to IP addresses.

Fix delivery failures in 5 steps

Follow these steps in order. Steps 1 and 2 are required for all senders who send more than 5,000 emails per day to Gmail addresses.

Step 1: Configure email authentication

Google requires all emails to have an authenticated sending identity. If you send more than 5,000 emails per day from a root domain, all three authentication protocols are required.

Configure each protocol at your DNS provider using the values from the Direct Mail console.

SPF

• Purpose: Prevents malicious actors from using your Direct Mail account to send fraudulent messages on behalf of your domain.

• How to configure: In your DNS provider, update the TXT record for your domain using the values shown in the Direct Mail console configuration table.

• For more information, see How to configure an email domain.

DKIM

• Purpose: Authenticates the sending domain by signing each message with a cryptographic signature. The signature also lets receiving servers verify that the message was not altered in transit.

• How to configure: In your DNS provider, update the TXT record for the specific DKIM domain name using the values shown in the Direct Mail console configuration table.

• For more information, see What is DKIM? How do I set up a DKIM record?

DMARC

• Purpose: Prevents domain spoofing by instructing receiving servers how to handle emails that fail SPF or DKIM checks. DMARC also delivers aggregate reports about authentication failures.

• How to configure: In your DNS provider, add a TXT record in the following format: v=DMARC1;p=none;rua=mailto:a@example.net;ruf=mailto:a@example.net. Replace the placeholder email addresses with real addresses for the rua and ruf parameters.

• For more information, see What is DMARC? How do I set up a DMARC record?

Step 2: Add a one-click unsubscribe option

Gmail requires marketing senders who send more than 5,000 emails per day to include a one-click unsubscribe button. For setup instructions, see Help with the unsubscribe feature.

Step 3: Monitor sender reputation with Postmaster Tools

Use Google Postmaster Tools to track your domain's reputation and spam rate. Open the Postmaster Tools management page, add the verification value that Gmail provides to your DNS configuration to confirm domain ownership. For setup instructions, see Related help.

Keep the spam rate below 0.1%. If the spam rate reaches 0.3%, Google applies penalties that lower your domain's reputation and cause subsequent emails to be rejected or routed to spam.

Step 4: Warm up new IP addresses

Always use a warm-up plan before sending at full volume from a new IP address. For a recommended schedule, see Warm-up recommendations.

Step 5: Check your domain's safety status

Check your domain's status with Google to verify it is not flagged for phishing or malware.

Still having delivery problems?

If the steps above do not resolve the issue, use Google's guided tool to troubleshoot email delivery issues for senders.