Why does mx.google keep refusing emails to gmail addresses

Question

Why does mx.google keep refusing emails to gmail addresses

stewart taylor 55

For the last few weeks any email i send to or reply to which is gmail, get refused by the recipient. Usualm with the following message

Your message wasn't delivered because the recipient's email provider rejected it.

mx.google.com gave this error:
This mail is unauthenticated, which poses a security risk to the sender and Gmail users, and has been blocked. The sender must authenticate with at least one of SPF or DKIM. For this message, DKIM checks did not pass and SPF check for

any ideas??

I haven't changed anything at my end that would lead to this.

yale 10 Reputation points

2023-03-29T00:50:07.4766667+00:00

I'm experiencing the same recently. The message from "******@outlook.com" says "While the sender may be able to alter the message contents to fix this, it's likely that only the recipient's email admin can fix this problem. Unfortunately, Office 365 support is unlikely to be able to help fix these kinds of externally reported errors." However, I have no idea how to contact the email admin. Moreover, no Office 365 support won't be able to help. This is FRUSTRATING.
rbnootan 5 Reputation points

2023-06-18T22:50:01.4+00:00

Last week I started getting the same error from google, and I have also not changed anything my end. What is going on?
Jason Mackey 5 Reputation points

2023-08-11T18:42:49.87+00:00

I checked the SPF record setup on my domain using Googles Admin Toolbox. Its setup correctly. I still get a bounceback when sending to gmail addresses intermittently. The weird part is sometimes they go through to gmail recipients and then other times when sending to a different gmail address they bounce with: "This mail is unauthenticated, which poses a security risk to the sender and Gmail users and has been blocked. The sender must authenticate with at least one of SPF or DKIM." Then I tested it by sending the same exact test email but sent it to two different gmail accounts at different times. One bounced and one was delivered. It makes no sense. I did find on a gmail help page that if an email is forwarded it may bounce for the same reason dkim/spf . It has to do with the original senders ip address and the person forwarding the email. The gmail server thinks the original sender sent the email but checks the forwarding mailbox's SPF record and they wont match.

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yale 10 Reputation points

2023-03-29T00:50:07.4766667+00:00

I'm experiencing the same recently. The message from "******@outlook.com" says "While the sender may be able to alter the message contents to fix this, it's likely that only the recipient's email admin can fix this problem. Unfortunately, Office 365 support is unlikely to be able to help fix these kinds of externally reported errors." However, I have no idea how to contact the email admin. Moreover, no Office 365 support won't be able to help. This is FRUSTRATING.
rbnootan 5 Reputation points

2023-06-18T22:50:01.4+00:00

Last week I started getting the same error from google, and I have also not changed anything my end. What is going on?
Jason Mackey 5 Reputation points

2023-08-11T18:42:49.87+00:00

I checked the SPF record setup on my domain using Googles Admin Toolbox. Its setup correctly. I still get a bounceback when sending to gmail addresses intermittently. The weird part is sometimes they go through to gmail recipients and then other times when sending to a different gmail address they bounce with: "This mail is unauthenticated, which poses a security risk to the sender and Gmail users and has been blocked. The sender must authenticate with at least one of SPF or DKIM." Then I tested it by sending the same exact test email but sent it to two different gmail accounts at different times. One bounced and one was delivered. It makes no sense. I did find on a gmail help page that if an email is forwarded it may bounce for the same reason dkim/spf . It has to do with the original senders ip address and the person forwarding the email. The gmail server thinks the original sender sent the email but checks the forwarding mailbox's SPF record and they wont match.

Answer 1

Hello,

SPF is a standard method of email authentication. This protects your domain from spoofing and prevents outgoing messages from being marked as spam by receiving servers. It also defines the mail servers that are allowed to send email for your domain. In inbound mail servers, SPF checks incoming messages that appear to come from your domain to make sure they were really sent from servers you authorized.

Without SPF, inbound servers are more likely to mark messages sent from your organization or domain as spam.

As of November 2022, new senders sending email to private Gmail accounts must set up either SPF or DKIM. Google performs random checks on messages from new senders to private Gmail accounts to determine if they have been authenticated. Messages without at least one of these authentication methods are rejected or marked as spam with the 5.7.26 error. This requirement does not apply to existing senders. However, we recommend that you always set up SPF and DKIM to protect your organization's email and meet future authentication requirements.

For more information on SPF, click here.

For more information on DKIM, click here.

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Why does mx.google keep refusing emails to gmail addresses

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