Emails being blocked by Gmail from office 365

Anonymous
2023-03-02T23:25:26+00:00

When the emails is sent to gmail its being blocked stating

Delivery has failed to these recipients or groups:

___@___.___ (***********@gmail.com)

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

all my records are up to date..

gmail.com suspects your message is spam and rejected it.

natasha.daniel Office 365 gmail.com
Sender Action Required
<br> --- --- --- --- ---
Messages suspected as spam
How to Fix It
Try to modify your message, or change how you're sending the message, using the guidance in this article: Bulk E-mailing Best Practices for Senders Using Forefront Online Protection for Exchange. Then resend your message.
If you continue to experience the problem, contact the recipient by some other means (by phone, for example) and ask them to ask their email admin to add your email address, or your domain name, to their allowed senders list.

Was this helpful?Send feedback to Microsoft.

More Info for Email AdminsStatus code: 550 5.7.350

When Office 365 tried to send the message to the recipient (outside Office 365), the recipient's email server (or email filtering service) suspected the sender's message is spam.

If the sender can't fix the problem by modifying their message, contact the recipient's email admin and ask them to add your domain name, or the sender's email address, to their list of allowed senders.

Although the sender may be able to alter the message contents to fix this issue, 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.

Original Message Details

Created Date: 3/2/2023 11:29:38 PM
Sender Address: *********@*****.com
Recipient Address: *********@gmail.com
Subject: Email check

Error Details

Reported error: 550 5.7.350 Remote server returned message detected as spam -> 550 5.7.1 [2a01:111:f403:700f::715 19] Our system has detected that this;message is likely suspicious due to the very low reputation of the;sending domain. To best protect our users from spam, the message has;been blocked. Please visit; https://support.google.com/mail/answer/188131 for more information. c23-20020aa7c997000000b004ace5dc6b61si945041edt.369 - gsmtp
DSN generated by: PN3P287MB0113.INDP287.PROD.OUTLOOK.COM
Outlook | Windows | Classic Outlook for Windows | For home

Locked Question. This question was migrated from the Microsoft Support Community. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.

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  1. Anonymous
    2024-04-22T14:06:25+00:00

    Issue: Your O365 hosted email bounces back as SPAM from any g-mail/google hosted domain.

    SOLUTION: Create a DMARC record for your domain

    The "TRUE" solution is to add a DMARC record to your domains DNS records.

    The thread that keeps on keeping on...

    @Michael B. I totally agree every domain should have a DMARC but I still do not agree this is the root cause of this issue. Why?

    As stated here "Messages that aren’t authenticated with these methods might be marked as spam or rejected with a5.7.26error." Email sender guidelines - Google Workspace Admin Help

    I would expect to see this error message or one of the others listed under 5.7.26.

    5.7.26 This mail has been blocked because the sender is unauthenticated. Gmail requires all senders to authenticate with either SPF or DKIM. Authentication results: DKIM = did not pass SPF [domain-name] with ip: [ip-address] = did not pass. For instructions on setting up authentication, go to Email sender guidelines. 

    NOT

    550 5.7.350 Remote server returned message detected as spam -> 550 5.7.1 Our system has detected that this; message is likely suspicious due to the very low reputation of the sending domain

    The bounce clearly states that the sending domain has a very low reputation. In simple terms this means that google has seen the domain relaying spam or other reputation related triggers. Granted having a DMARC record might help the domain reputation but in my opinion it's not the root cause of the issue but that's just my 2 cents.

    Br.

    Joshua

    P.S. RUF is not recommended if you are in the EU as it is not GDPR compliant. It's also important to note, if you use RUF or RUA you should use a email address with the same domain unless you setup some wildcard DNS responders like all DMARC reporting services.

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  2. Anonymous
    2024-04-22T14:03:20+00:00

    @Pavlína Kvapilová,

    The issue you are seeing has to do with using the country domain outlook.cz. There is a Known Issue posted about it at the top of the list for Outlook.com known issues, Fixes or workarounds for recent issues on Outlook.com - Microsoft Support. A workaround would be to create an Outlook.com alias such as ******@outlook.com and when you send to Gmail click the From drop down and send from that domain.

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  3. Anonymous
    2024-04-22T12:20:38+00:00

    Hi, I will be updating the original post shortly. The solution *no longer works*, as it was a temp fix to a larger problem.

    The "TRUE" solution is to add a DMARC record to your domains DNS records. I won't go into details of what dmarc is, but you can read it here: https://dmarc.org/  . The simplified version is that "YOU" are sent reports by ISPs regarding how your domain name is being used.

    **If you do not know how to add a record into your DNS server, contact the person who manages it for you".

    The record is very easy to build. It requires sending to an valid email address. I strongly recommend creating "THIS/AN" special email address (a group based distribution list that can receive email from outside your org). I use dmarc@ for all my domains email.

    The format in DNS is as follows

    HOST: _dmarc

    VALUE: v=DMARC1; p=none; rua=mailto:YourEmailAddress; ruf=mailto:YourEmailAddress fo=1:d:s

    TTL: I prefer 1Hour but you can choose anything.

    Once it is set up correctly, you can test this by going to https://mx****/dmarc.aspx (mx****)

    That is all there is too it. No need for special mail flow rules.

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  4. Anonymous
    2024-04-22T11:25:24+00:00

    I am having this issue as well... Tried to follow your steps but during validation I get the error "Error executing request. Smart-hosting for this recipient domain is not supported.".

    Any ideas?

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  5. Anonymous
    2024-04-08T10:12:41+00:00

    I stopped my recurring payment for Office 365. Microsoft is full of incapable people who don't care about their customers.

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