Why is Gmail rejecting unauthenticated email from gmail.com due to DMARC policy when sending via Sendgrid?

Summary

Gmail rejects unauthenticated emails from @gmail.com when sent via SendGrid due to DMARC policy enforcement. This is because DMARC, along with SPF and DKIM, authenticates email senders and prevents spoofing. For DMARC to pass, the 'From' address domain must align with the domain used for SPF or DKIM. Since SendGrid is not authorized to send on behalf of Gmail, emails using a 'gmail.com' 'From' address will fail DMARC checks, resulting in rejection. Sending from a freemail domain for bulk mail is generally a bad idea. The best practice is to use a domain you own and properly authenticate it with SPF, DKIM, and DMARC to ensure your emails are delivered successfully.

Key findings

  • DMARC Enforcement: Gmail actively enforces DMARC policies to protect against email spoofing and phishing.
  • Authentication Failure: Sending emails from '@gmail.com' via SendGrid fails DMARC checks due to a lack of SPF and DKIM alignment.
  • Domain Alignment: DMARC requires that the domain in the 'From' address aligns with the SPF or DKIM authenticated domain.
  • Freemail Issues: Using free email domains for bulk mail is a bad practice and may lead to deliverability problems.

Key considerations

  • Domain Ownership: Use a domain you own and control for sending emails.
  • Authentication Protocols: Properly configure SPF, DKIM, and DMARC for your domain to authenticate your emails.
  • Avoid Spoofing: Avoid using 'From' addresses that you are not authorized to send from, as it leads to DMARC failures and rejection.
  • DMARC Compliance: Comply with DMARC requirements to ensure your emails are delivered successfully and to protect your domain from spoofing.

What email marketers say
12Marketer opinions

Gmail rejects unauthenticated emails from @gmail.com sent via SendGrid due to its enforcement of DMARC policies. DMARC, along with SPF and DKIM, are email authentication methods designed to prevent spoofing. When sending emails from SendGrid while using a 'From' address of '@gmail.com', the email fails DMARC checks because SendGrid is not authorized to send on behalf of Gmail. This lack of alignment between the 'From' domain and the sending source triggers Gmail's DMARC policy, resulting in rejection. To avoid this, senders should use a domain they own and properly authenticate it using SPF, DKIM, and DMARC, ensuring that these protocols align with the 'From' address.

Key opinions

  • DMARC Enforcement: Gmail actively enforces DMARC policies to protect users from spoofing and phishing.
  • Authentication Failure: Sending emails from '@gmail.com' via SendGrid fails DMARC checks due to lack of SPF/DKIM alignment.
  • Domain Ownership: Using a domain you own and properly authenticating it is crucial for passing DMARC checks.
  • Spoofing Prevention: DMARC is designed to prevent unauthorized use of domains and protect against email spoofing.

Key considerations

  • Domain Authentication: Implement SPF, DKIM, and DMARC records for your sending domain to establish trust with email providers.
  • Alignment Checks: Ensure that SPF and DKIM align with the 'From' address domain to pass DMARC authentication.
  • Sender Reputation: Failing DMARC checks can negatively impact your sender reputation and email deliverability.
  • Avoid Spoofing: Refrain from using 'From' addresses that you are not authorized to send from to prevent DMARC failures and potential rejection.
Marketer view

Marketer from Email Geeks explains that long before DMARC, DKIM, or SPF, it was possible and sometimes advisable for domains to reject “internal” mail from external sources. He suggests that Gmail's policy might be to reject inbound mail using gmail.com in the From: domain if it doesn't pass DMARC validation.

July 2024 - Email Geeks
Marketer view

Email marketer from Reddit explains that for DMARC to pass, either SPF or DKIM must align with the 'From' address. If you're sending from Sendgrid but using a 'gmail.com' From address, neither SPF nor DKIM will align, causing DMARC to fail and Gmail to reject the email.

May 2023 - Reddit
Marketer view

Email marketer from Neil Patel explains that when DMARC fails, it means your email isn't properly authenticated, leading to potential rejection by email providers like Gmail. This happens because the email appears to be spoofed, harming your sender reputation and deliverability.

July 2024 - Neil Patel
Marketer view

Email marketer from Postmark explains that the key to passing DMARC is alignment. If you are sending mail using Sendgrid, you need to use a 'From' address that is associated with a domain you control and that you have configured to work with Sendgrid. Otherwise, the DMARC check will fail and the email will likely be rejected or sent to spam.

August 2023 - Postmark
Marketer view

Email marketer from EasyDMARC explains that to pass DMARC, the domain in the 'From' address must align with either the SPF or DKIM authenticated domain. Sending an email from 'gmail.com' via SendGrid, where SendGrid isn't authorized to send on behalf of Gmail, causes this alignment to fail, leading to DMARC failure and potential rejection.

July 2024 - EasyDMARC
Marketer view

Marketer from Email Geeks advises to stop sending mail using a domain you do not own or control through servers which are not authorized to send mail for that domain. If you want to send mail using gmail.com, send it through and authenticate via gmails SMTP servers.

October 2022 - Email Geeks
Marketer view

Email marketer from Mailjet responds that the best practice is to use your own domain to send emails and properly authenticate it with SPF, DKIM, and DMARC. This confirms that you have permission to send emails on behalf of your domain, preventing them from being rejected.

July 2022 - Mailjet
Marketer view

Marketer from Email Geeks states that technically Gmail can do whatever they want with mail entering their system, especially that which impersonates their own domain. Their DMARC record recommends to other mailbox providers what should be done with mail that doesn't align.

September 2024 - Email Geeks
Marketer view

Email marketer from AuthSMTP responds that the recommended approach is to use your own domain for sending email. This allows you to fully control the authentication process. If you try to send from a 'gmail.com' address via SendGrid, you are essentially spoofing, which will result in DMARC failures.

April 2024 - AuthSMTP
Marketer view

Email marketer from StackOverflow shares that the issue is due to DMARC's alignment requirements. When sending via Sendgrid, and using a Gmail address, the email fails SPF and DKIM. Gmails policy is to reject emails that fail this.

November 2021 - StackOverflow
Marketer view

Email marketer from Email Hippo shares that to improve deliverability, send from a domain you control and set up SPF, DKIM, and DMARC correctly. Sending from a 'gmail.com' address through SendGrid is impersonation and will likely be rejected by Gmail.

August 2022 - Email Hippo
Marketer view

Email marketer from SparkPost shares that setting up proper DMARC records helps ensure your emails are authenticated correctly. When sending from SendGrid, use a domain you own and configure SPF and DKIM to align with the 'From' address. This will help you pass DMARC checks and avoid being rejected by Gmail.

July 2023 - SparkPost

What the experts say
3Expert opinions

Gmail rejects unauthenticated emails claiming to be from @gmail.com when sent through SendGrid due to strict DMARC enforcement. Using free email domains like Gmail for bulk mail is generally discouraged, as it's often seen as a spam indicator. DMARC is specifically designed to prevent unauthorized use of a domain by instructing receiving mail servers on how to handle emails that fail authentication checks (SPF and DKIM). Gmail actively enforces its DMARC policy, rejecting emails that appear to originate from Gmail but aren't properly authenticated by Gmail itself.

Key opinions

  • FreeMail Bad for Bulk: Using free email domains for bulk sending is a bad practice.
  • DMARC Enforcement: Gmail aggressively enforces DMARC to prevent domain spoofing.
  • DMARC Function: DMARC is designed to prevent unauthorized use of a domain by providing instructions to receiving servers.

Key considerations

  • Authentication: Ensure your emails pass SPF and DKIM checks to avoid DMARC failure.
  • Domain Control: Use a domain you control for sending emails and authenticate it correctly.
  • Bulk Mail Practices: Avoid using free email domains for sending bulk emails.
Expert view

Expert from Email Geeks states it's generally a bad idea to use a freemail domain for bulk mail, considering it a spam sign. She advises buying a domain and configuring it for commercial bulk mail.

April 2024 - Email Geeks
Expert view

Expert from Spam Resource (John Levine) explains that Gmail is aggressively enforcing DMARC policies, especially regarding emails claiming to be from gmail.com but originating from other sources. Sending from SendGrid using a gmail.com 'From' address fails DMARC checks because SendGrid isn't authorized to send on behalf of Gmail, resulting in rejection.

January 2025 - Spam Resource
Expert view

Expert from Word to the Wise (Laura Atkins) responds that DMARC is explicitly designed to prevent the type of behavior you're describing. It's a way for domain owners (like Gmail) to tell receiving mail servers (other ISPs or corporate email systems) how to handle mail that claims to be from their domain but fails authentication checks (SPF and DKIM). Gmail has a strict DMARC policy to reject unauthorized use of @gmail.com.

May 2021 - Word to the Wise

What the documentation says
5Technical articles

Gmail rejects unauthenticated emails from @gmail.com sent via SendGrid because of DMARC policies designed to prevent email spoofing and phishing. DMARC instructs receiving servers how to handle emails claiming to be from a specific domain that fail SPF and DKIM authentication checks. For DMARC to pass, the 'From' address domain must align with the domain used for SPF or DKIM. Sending from SendGrid with a @gmail.com 'From' address will fail because SendGrid isn't authorized to send on behalf of Gmail. This aligns with the DMARC specification (RFC 7489), where email receivers should handle messages that fail authentication.

Key findings

  • DMARC Purpose: DMARC prevents email spoofing by allowing domain owners to specify how unauthenticated emails from their domain should be handled.
  • Alignment Requirement: DMARC requires the 'From' address domain to align with the SPF or DKIM authenticated domain.
  • Gmail Compliance: Gmail adheres to the DMARC specification (RFC 7489) by rejecting unauthenticated emails from gmail.com sent via third-party services.
  • SPF Purpose: SPF records help prevent email forging.

Key considerations

  • Authentication Setup: Configure SPF and DKIM records to properly authenticate your domain for email sending.
  • Domain Authorization: Only send emails from domains you are authorized to send from.
  • DMARC Policy: Understand and implement a DMARC policy to protect your domain from email spoofing.
  • SPF Record Setup: Configure SPF records to specify which hosts are allowed to send from your domain.
Technical article

Documentation from Google Workspace Admin Help explains that if an email claims to be from your domain but doesn't pass SPF or DKIM checks, DMARC tells receiving servers what to do with it. Gmail may reject these emails if your DMARC policy is set to 'reject' or if it identifies the email as suspicious.

September 2023 - Google Workspace Admin Help
Technical article

Documentation from DMARC.org explains that DMARC helps prevent email spoofing by allowing domain owners to specify how receiving mail servers should handle unauthenticated emails that appear to be from their domain. Gmail is likely rejecting the emails to protect its users from phishing and spam.

November 2021 - DMARC.org
Technical article

Documentation from Microsoft explains that Sender Policy Framework (SPF) is an email authentication method designed to detect forging sender addresses during the delivery of email. SPF allows administrators to specify which hosts are allowed to send mail from a given domain by creating a specific (TXT) record in the DNS. When Gmail receives mail from sendgrid but that email is claiming to be from @gmail, the SPF check will fail, as Sendgrid servers are not allowed to send from gmail.com

May 2022 - Microsoft
Technical article

Documentation from SendGrid Support shares that for DMARC to pass, the domain in the 'From' address must align with the domain used for SPF or DKIM. Sending from 'gmail.com' via SendGrid will likely fail DMARC because SendGrid is not authorized to send on behalf of Gmail.

November 2024 - SendGrid Support
Technical article

Documentation from RFC Editor (RFC 7489) shares that the DMARC specification describes how email receivers should handle messages that fail authentication checks. Gmail is adhering to this specification by rejecting unauthenticated emails from gmail.com when sent through third-party services like SendGrid.

July 2023 - RFC Editor