How does Google Workspace manage outbound authentication with multiple domains?

Summary

Google Workspace allows adding multiple domains, requiring independent DKIM configuration for each. A domain alias can inherit or have separate DKIM settings, requiring manual key setup. SPF records should include all sending sources or `include:_spf.google.com`. DMARC should be set up and monitored for each domain. Common issues include DKIM misconfiguration, incorrect SPF records, and failing DMARC alignment. Regular DMARC report reviews and DNS record verification are crucial. User configurations like 'send as' can cause DKIM mismatch. Legacy Google for Work editions may have unstable authentication. Domain aliases might default to authenticating with only the main domain.

Key findings

  • Individual DKIM Config: Each domain requires independent DKIM configuration in the Google Workspace admin panel.
  • SPF Inclusion: SPF records should include all sending domains and IPs, or use 'include:_spf.google.com'.
  • DMARC Monitoring: DMARC policies must be set up for each domain, with regular monitoring.
  • Common Issues: Misconfigured DKIM keys, incorrect SPF records, and DMARC alignment failures are frequent problems.
  • Multiple Domains: You can add multiple domains including aliases and seperate domains.

Key considerations

  • User Configuration: User configurations using 'send as' can lead to DKIM mismatches.
  • Legacy Accounts: Older Google for Work accounts may have unreliable authentication processes.
  • DNS Verification: Verify SPF, DKIM, and DMARC records for each domain using online tools to ensure function.
  • Key Rotation: Regular rotation of DKIM keys (every 3-6 months) is recommended to improve authentication practices.
  • Alternative Accounts: Rather than aliases use individual accounts.

What email marketers say
12Marketer opinions

Google Workspace handles outbound authentication with multiple domains by requiring individual DKIM configuration for each domain within the admin panel. Domain aliases can inherit settings or be configured separately. Proper SPF records, including all sending domains, and individual DMARC policies per domain are crucial. Common issues involve misconfigured DKIM keys, incorrect SPF records, and alignment failures. Regularly reviewing DMARC reports and using online tools for verification are essential for maintaining authentication.

Key opinions

  • DKIM Configuration: Each domain in Google Workspace must have DKIM configured independently.
  • Domain Aliases: Domain aliases can either inherit authentication settings from the primary domain or have separate configurations.
  • SPF Records: SPF records should include all sending domains and IPs, or use `include:_spf.google.com`, adhering to DNS lookup limits.
  • DMARC Policies: DMARC policies should be set up independently for each domain, with regular monitoring of DMARC reports.
  • Troubleshooting: Common authentication issues include misconfigured DKIM keys, incorrect SPF records, and failure to align From addresses.

Key considerations

  • User Configuration: Incorrect user configurations, such as using aliases and send-as features, can cause authentication issues.
  • Legacy Accounts: Legacy 'free' Google for Work accounts may have unreliable authentication.
  • DNS Consistency: Ensuring consistent and correct DNS records across all domains is critical.
  • DMARC Reporting: Regularly review DMARC reports to identify and address authentication discrepancies.
  • Verification Tools: Use online tools to verify the correct setup of SPF, DKIM, and DMARC records.
Marketer view

Marketer from Email Geeks says if the client is on the ancient legacy "free" edition of Google for Work then authentication is wobbly in general.

July 2021 - Email Geeks
Marketer view

Email marketer from StackExchange shares that each domain needs to have DKIM configured independently in the Google Workspace admin panel.

July 2023 - StackExchange
Marketer view

Email marketer from Mailhardener Blog suggests using online tools to verify SPF, DKIM, and DMARC records for each domain to ensure proper setup and function.

March 2023 - Mailhardener Blog
Marketer view

Email marketer from Superuser notes that domain aliases inherit the primary domain's authentication settings unless specifically configured otherwise.

January 2022 - Superuser
Marketer view

Email marketer from EmailDiscussions.com stresses that ensuring DNS records are correctly and consistently set up across all domains within the Google Workspace organization is crucial for proper outbound authentication.

May 2021 - EmailDiscussions.com
Marketer view

Marketer from Email Geeks shares his knowledge that if two domains are set up independently in Google Workspace, DKIM signing domain mismatch occurs when a user at Domain A configures their address at Domain B as an alias/send-as within their Gmail on Domain A.

January 2024 - Email Geeks
Marketer view

Email marketer from EmailGeeks Forum explains setting up DMARC policies for each domain independently and monitoring DMARC reports to identify and address any authentication issues.

June 2023 - EmailGeeks Forum
Marketer view

Marketer from Email Geeks explains that if a second domain is set up as an alias, it can have its own DKIM signing domain, but the 5321.From domain is that of the main domain. Also that key generation is not automatic for a second domain, it has to be setup in the admin panel.

January 2025 - Email Geeks
Marketer view

Email marketer from Reddit advises including all sending domains and IPs in your SPF record or using include:_spf.google.com, and ensuring there are no more than 10 DNS lookups.

August 2023 - Reddit
Marketer view

Email marketer from MXToolbox Forum points out that common issues include misconfigured DKIM keys, incorrect SPF records, and failing to align the From address with DKIM and SPF.

September 2024 - MXToolbox Forum
Marketer view

Email marketer from Email Security Blog highlights the need for regularly analyzing DMARC reports to identify any discrepancies or failures in outbound email authentication across the managed domains.

February 2022 - Email Security Blog
Marketer view

Marketer from Email Geeks guesses that if the authentication issue isn't universal, then one or more users have configured their Gmails to send on behalf of the other domain.

May 2021 - Email Geeks

What the experts say
3Expert opinions

Managing outbound authentication with multiple domains in Google Workspace can present challenges. One expert encountered an issue where Google refused to sign with the proper DKIM key despite multiple resets. Regular DKIM key rotation (every 3-6 months) is important for security. A workaround for authentication problems involved creating multiple user accounts instead of using domain aliases and 'send as' functionality.

Key opinions

  • DKIM Key Issues: Google Workspace may sometimes fail to sign emails with the correct DKIM key, even after resetting.
  • DKIM Rotation: Regular DKIM key rotation is essential for maintaining security when using multiple domains.
  • Authentication Problems: GSuite might default to authenticating using only one domain, causing issues with multiple domain setups.

Key considerations

  • Key Rotation Schedule: Implement a schedule for rotating DKIM keys every 3-6 months.
  • User Account Strategy: Consider using multiple user accounts instead of aliases to ensure proper authentication for each domain.
  • Troubleshooting Steps: Be prepared to troubleshoot DKIM signing issues and explore alternative configurations.
Expert view

Expert from Word to the Wise shared that, for them, a huge problem was that GSuite was authenticating using one domain, when there were multiple domains set up. She got around this by creating multiple user accounts instead of aliases and sending as separate accounts.

January 2025 - Word to the Wise
Expert view

Expert from Spam Resource explains that when using multiple domains in Google Workspace, it's important to rotate DKIM keys regularly for each domain to maintain security. Dave recommends rotating every 3-6 months.

October 2024 - Spam Resource
Expert view

Expert from Email Geeks has the same issue with one domain where Google refuses to sign with the proper key even after trying to reset it multiple times and has not found any solutions after searching for some time.

September 2023 - Email Geeks

What the documentation says
5Technical articles

Google Workspace allows the addition of multiple domains, including separate domains, domain aliases, and subdomain aliases, to a single account. Each domain requires individual DKIM setup, involving key generation and TXT record configuration in DNS. Google recommends including `include:_spf.google.com` in SPF records. DMARC is supported, enabling policy creation and reporting for handling emails failing SPF or DKIM. Troubleshooting steps involve verifying DNS records, DKIM configuration, and DMARC settings for each domain.

Key findings

  • Multiple Domains: Google Workspace supports separate domains, domain aliases, and subdomain aliases.
  • DKIM Setup: Each domain requires individual DKIM key generation and TXT record addition.
  • SPF Recommendation: Use `include:_spf.google.com` in SPF records.
  • DMARC Support: DMARC is supported with policy creation and reporting features.
  • Troubleshooting: Troubleshooting involves verifying DNS records, DKIM, and DMARC settings.

Key considerations

  • Individual Configuration: Remember that each domain needs its own specific authentication configuration.
  • Regular Monitoring: Continuously monitor DMARC reports to ensure proper authentication.
  • DNS Record Accuracy: Double-check the accuracy of all DNS records, including SPF, DKIM, and DMARC.
Technical article

Documentation from Google Workspace Admin Help explains how DMARC works with Google Workspace, how to create DMARC policy to tell recipient servers what to do with messages from your domain that don’t pass SPF or DKIM. Also how to set up DMARC reporting to help you monitor the email sent from your domain.

November 2022 - Google Workspace Admin Help
Technical article

Documentation from Google Workspace Admin Help details the steps for setting up DKIM for each domain, including generating DKIM keys and adding the TXT record to each domain's DNS settings.

May 2024 - Google Workspace Admin Help
Technical article

Documentation from Google Workspace Admin Help explains that you can add multiple domains to your Google Workspace account. This allows you to add user aliases and more domains that your company owns. These can be separate domains, domain aliases, or subdomain aliases.

August 2024 - Google Workspace Admin Help
Technical article

Documentation from Google Workspace Admin Help recommends using `include:_spf.google.com` in your SPF record to authorize Google Workspace to send emails on behalf of your domain. They also recommend including all your sending sources in the SPF.

August 2024 - Google Workspace Admin Help
Technical article

Documentation from Google Workspace Admin Help provides steps for troubleshooting common email authentication issues, including verifying DNS records, checking DKIM key configuration, and reviewing DMARC settings for each domain.

June 2024 - Google Workspace Admin Help