Email sent through SMTP (smtp.office365.com) is being flagged as SPAM

Email sent through SMTP (smtp.office365.com) is being flagged as SPAM by many recipient mail servers whereas email sent from the Outlook client is not.  We've done side-by-side tests where we sent the same message from the same account, to the same recipient and the one sent through smtp.office365.com often gets flagged as SPAM.  We have SPF and DKIM in place but the problem seems to be the mail server's IP (104.47.32.210) is on several blacklists.

* Please try a lower page number.

* Please enter only numbers.

* Please try a lower page number.

* Please enter only numbers.

Hello Dmack,

Did you confirm with the recipient side? If they add the IP into their allow list, will the email being flagged as SPAM? I have checked that this IP is not blocked in multiple blacklists. If you still need further help, please send me the message header of the email which was flagged as spam. I will send  you a private message (https://answers.microsoft.com/en-us/privatemessages/list)to collect it.

Thanks,

Alison

Did this solve your problem?

Sorry this didn't help.

Great! Thanks for marking this as the answer.

How satisfied are you with this reply?

Thanks for your feedback, it helps us improve the site.

How satisfied are you with this response?

Thanks for your feedback.

Hello Dmack,

Do you have any update on this?

Looking forward,

Alison

Did this solve your problem?

Sorry this didn't help.

Great! Thanks for marking this as the answer.

How satisfied are you with this reply?

Thanks for your feedback, it helps us improve the site.

How satisfied are you with this response?

Thanks for your feedback.

I have checked the IP with several 3rd party blacklist databases.  For example

https://mxtoolbox.com/SuperTool.aspx?action=blacklist%3a104.47.32.210&run=toolpage

Yes I confirmed with the client side.  Many of the messages come back to us as rejected and Outlook gives the following reason.


Error Details
Reported error: 550 5.7.350 Remote server returned message detected as spam -> 554 5.7.1 The message from (<email not shown>) with the subject of (We're Sorry to See You Go) matches a profile the Internet community may consider spam. Please revise your message before resending.
DSN generated by: SN2PR03MB2144.namprd03.prod.outlook.com
Remote server: atl4mhib54.myregisteredsite.com

Did this solve your problem?

Sorry this didn't help.

Great! Thanks for marking this as the answer.

How satisfied are you with this reply?

Thanks for your feedback, it helps us improve the site.

How satisfied are you with this response?

Thanks for your feedback.

Hello Dmack,

Yes, I saw the IP was blocked in MxToolBox but I cannot determine that the issue is related to IP based on the NDR you provided. Did you saw the original message header in the NDR? If yes, please share the entire content.

Since you are trying to relay your mail throuth the SMTP server, could you please let me know if all the requirements are met in your case? Here is the reference, you may use the client submission.

https://support.office.com/en-us/article/How-to-set-up-a-multifunction-device-or-application-to-send-email-using-Office-365-69f58e99-c550-4274-ad18-c805d654b4c4

There may be serveral reasons such as you are trying to relay your mail through another SMTP server, and that server does not allow you to relay. Or the recipient might have mailbox delivery restrictions enabled. For example, a recipient's mailbox delivery restriction was set to receive from a Distribution List only, and the email message of a non-member is rejected and generates this error.

Thanks,

Alison

Did this solve your problem?

Sorry this didn't help.

Great! Thanks for marking this as the answer.

How satisfied are you with this reply?

Thanks for your feedback, it helps us improve the site.

How satisfied are you with this response?

Thanks for your feedback.

Hello Dmack,

Please take your time and share any updates at your convenience.

 

Looking forward.

Alison

Did this solve your problem?

Sorry this didn't help.

Great! Thanks for marking this as the answer.

How satisfied are you with this reply?

Thanks for your feedback, it helps us improve the site.

How satisfied are you with this response?

Thanks for your feedback.

Your message to *** Email address is removed for privacy *** couldn't be delivered.
When Office 365 tried to send your message, the receiving email server outside Office 365 reported an error.
alamb Office 365 xxxxxx
Sender Action Required
         
Policy violation or system error
 
How to Fix It
Check the "Reported Error" from the "Error Details" section shown below for more information about the problem. The error might tell you what went wrong and how to fix it. For example, if the error states that the message was blocked due to a potential virus or because the message was too large, try sending the message again without attachments.
If you're not able to fix the problem, it's likely that only the recipient's email admin can fix it. Contact the recipient by some other means (by phone, for example) and ask them to tell their email admin about the problem. Give them the "Reported Error" from the "Error Details" section below.

Was this helpful? Send feedback to Microsoft.

More Info for Email Admins
Status code: 550 5.0.350

The error reported by the receiving server wasn't specific enough to determine the exact nature of the problem. These errors often indicate the message violates a security or policy setting configured on the recipient's email servers.

If the sender is unable to fix the problem by modifying their message, then it's likely a problem that only the recipient's email admin can fix. Try the following:

Check the error for information about the problem - The "Reported Error" returned by the external email server can be found in the "Error Details" section below. This error might tell you what went wrong and provide clues for how to fix it. For example, if the error states the message was rejected due a Sender Policy Framework (SPF) issue, then you'll have to work with your domain registrar to correctly configure your domain's SPF records.

Check the error for information about where the problem is happening - For example, look for a domain name like contoso.com. A domain name in the error might suggest who is responsible for the error. It could be the recipient's email server, or it could be a third-party service that your organization or the recipient's organization is using to process or filter email messages.

If you can't fix the problem, contact the responsible party's email admin - Give them the error code and error message from this non-delivery report (NDR) to help them troubleshoot the issue. For security or policy violation issues, it might be sufficient for them to just add your sending IP addresses or domain to their allowed senders list.

It's likely that only the recipient's email admin can fix the problem. Unfortunately, it's unlikely Office 365 Support will be able to help with these kinds of externally reported errors.
Original Message Details
Created Date: 6/6/2017 6:23:29 PM
Sender Address: *** Email address is removed for privacy ***
Recipient Address: *** Email address is removed for privacy ***
Subject: Choose the Best Events for Lancaster Elks Lodge

Error Details
Reported error: 550 5.0.350 Remote server returned an error -> 554 delivery error: dd This user doesn't have a yahoo.com account (*** Email address is removed for privacy ***) [0] - mta1489.mail.gq1.yahoo.com
DSN generated by: SN2PR03MB2141.namprd03.prod.outlook.com
Remote server: mta1489.mail.gq1.yahoo.com
Message Hops
HOP TIME (UTC) FROM TO WITH RELAY TIME
1 6/6/2017
6:23:36 PM
[64.xx.xxxx.130] SN2PR03MB2141.namprd03.prod.outlook.com Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) 7 sec

Remove message header and related information for your privacy.

Did this solve your problem?

Sorry this didn't help.

Great! Thanks for marking this as the answer.

How satisfied are you with this reply?

Thanks for your feedback, it helps us improve the site.

How satisfied are you with this response?

Thanks for your feedback.

Alison,

Let me know if I have not provided what you asked for.  Also, please confirm this is a private conversation.  

Thanks

Dmack

Did this solve your problem?

Sorry this didn't help.

Great! Thanks for marking this as the answer.

How satisfied are you with this reply?

Thanks for your feedback, it helps us improve the site.

How satisfied are you with this response?

Thanks for your feedback.

Here is more information that may help.   I've sent 2 messages to a mail test service.  One shows that one IP is on blacklists and the other is not.

Remove the address for your privacy.


Dmack


Did this solve your problem?

Sorry this didn't help.

Great! Thanks for marking this as the answer.

How satisfied are you with this reply?

Thanks for your feedback, it helps us improve the site.

How satisfied are you with this response?

Thanks for your feedback.

Hello Dmack,

I have analyzed the message header. Thank you for your reply.

This message was treated as spam by the Exchange Online Protection, the SCL was 5, The message was marked as spam by the content filter and the SPF was None. Then, the message was sent to the recipient via High Risk Delivery Pool. It may be rejected by the recipient mail services. About that, you can run a "message trace" in Exchange Admin Center to get the detailed process.

I have checked your SPF records, could you please just add the ip4: 67.xx.xxx.130 directly? (Fill in the corrent IP instead of the xxx). Then try changing the -all to ~all, will it work?

Best regards,

Alison

Did this solve your problem?

Sorry this didn't help.

Great! Thanks for marking this as the answer.

How satisfied are you with this reply?

Thanks for your feedback, it helps us improve the site.

How satisfied are you with this response?

Thanks for your feedback.

Alison,

I looked at the message trace and noticed many messages are marked as spam and sent via High Risk Delivery Pool as you have indicated.

I have added ip4:64xx.1xxx.130 ip4:64.xxx.1xxx.1xxxxip4:64.xx.1xxx.1xxxx as well as changed -all to ~all in the SPF record.  Our preliminary tests show no improvement.

How do we get Exchange Online Protection to not mark as spam?

Dmack

Did this solve your problem?

Sorry this didn't help.

Great! Thanks for marking this as the answer.

How satisfied are you with this reply?

Thanks for your feedback, it helps us improve the site.

How satisfied are you with this response?

Thanks for your feedback.

* Please try a lower page number.

* Please enter only numbers.

* Please try a lower page number.

* Please enter only numbers.

 
 

Question Info


Last updated October 5, 2020 Views 2,184 Applies to: