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

Copper Contributor

Dear all,


Recently, I registered 1 account Office 365 trial to experience O365 E3 version before bought it, I create a sharepoint site, upload some document and share with somebody, both the same and diffrence trial domain & gmail also. The share function working well, but email notification seem to be getting issue as below. Please help to advise me.


PS: I search some conversation get the same my issue and they advise ask recipient admin unblock some policies and mechanisms that block my Office 365 email address and directly contact the recipient’s admin for support. I'm IT person and I believe there is no any specific policy that block my trial domain.


Diagnostic information for administrators:

Generating server:
Remote Server returned '550 5.7.501 Service unavailable. Spam abuse detected from IP range. For more information please go to S(2017052602) []'

Original message headers:

Received: from
 ([fe80::5970:b751:c67f:bc77]) by
 ([fe80::5970:b751:c67f:bc77%2]) with mapi id 15.20.1965.017; Thu, 13 Jun 2019
 07:34:39 +0000
MIME-Version: 1.0
Content-Type: text/plain
Date: Thu, 13 Jun 2019 07:34:39 +0000
60 Replies

Hi All,


I have just found the fix mentioned in this thread


Basically, change the Outbound Spam Filter Policy to "On - Forwarding is enabled" by following this link


It works for me straight away.



I had the same issue and, I spoke the Microsoft support. The rep. gave me this solution below that worked for me-


1. Login to Admin panel 

2. Under Admin Center Click on "Security"

3. Click on "Threat Management"

4. Click on "Policy" under Threat Management 

5. Click on "Anti Spam"

6. Expand "Outbound spam filter policy"

7. Click on "Edit Policy"

8. Expand "Automatic forwarding"

9. Put in on "On- Forwarding is enabled"

10. Save and close the window.


Thanks :)

This article explains how to enable external forwarding and that was the reason, the mails were blocked. My users set automatic forwarding of there mail messages to another work account. After allowing forwarding for these users in the antispam rule it worked.
I have found out that it only says it with public email and not private ones.
If you attempt to email a popular public domain such as ‘gmail’ then it will show that message
If you email a private or organisation domain it won’t show the message.

I just experienced this issue, trying to forward to my wife's email address (we both have Outlook email addresses)  A notification from Paypal was forwarded, and rejected numerous times.  Other emails I sent to her as a test, are accepted. She has accepted me as a safe sender and domain.  I reset her Spam/Junk to Low.    We've both been using the Outlook accounts for several months now, and until today, without issue.



Someone guide me on this. Im getting the same error when I try to sen dmails from Exchnage 2013 to gmail

I am currently experiencing this kind of problem. May I know how did you resolve this?

@Ricky_Q   This is unresolvable, by anyone other than Microsoft, and they don't seem to give a crap.

Hello I'm having the same problem, any solution yet?
No solution, happens about every other day, MS does not seem to care. Curious, do you have a paid version of Outlook365 (subscription). They are pushing that at $99/year. I already paid $400 for MS Office, so thought I didn't need this.
I'm having the same issue trying to send to an email account. My email is one I've been using for 10+ years, so not new. Here's the text I get in the email failure notice: (who I'm sending the email to)
Your message couldn't be delivered because the recipient's email server (outside of Office 365) rejected it because it couldn't determine if your message is coming from a location that is associated with your email domain. This is a security measure commonly done to help prevent malicious email or spam email from entering the recipient's email system. The reason the lookup failed is likely because your domain's email settings aren't set up correctly. To fix this, forward this non-delivery report (NDR) to your email admin.

For Email Admins
When Office 365 tried to send the message to the recipient's email server (outside Office 365), the external email server returned the error below. This means that when the recipient's email server was asked to accept the sender's message the server likely performed a reverse DNS (rDNS) lookup and the lookup failed. An email server outside Office 365 may perform an rDNS lookup to validate that the IP address the message is coming from is associated with your domain. The failed rDNS lookup suggests that the PTR record (pointer DNS record type) for your domain isn't set up properly.

To fix this, work with your DNS hosting provider (your domain registrar, Web hosting provider, or ISP) to set up a correct PTR record for your domain. If you're using Office 365 to manage your DNS records note that PTR record creation and management isn't supported by the Office 365 interface, in which case you'll have to change your DNS management to a DNS host outside Office 365. Refer to this article for instructions on how to do this:Change how DNS records are managed with Office 365.

Setting up PTR records is not supported by Office 365. Office 365 support will not be able to help you fix this problem.


I too am using Hotmail/Live and am finding this happening to me now in March 2022.
Anyone explain why this should be?
Win10, constantly updated Firefox, Mobile internet tether.

@Paul_Edin If it is a new account, Microsoft puts limit on how many recipients (BCC only?) can be on an email. If you go over that amount (not stated anywhere I could find), then you'll get this error & many of the recipients (or maybe all [not sure]) will not receive the email. This is used as an antispam method, but the 1st thing often needed when getting a new account where the old account is not available is to tell all contacts the new email address :(. Longer term, they should allow more & more recipients.

Hope This Helps,


@Andy-the-GI made no mention of sending to multiple recipients because I never made any emails to multiple recipients.


Hey, have you seen/heard of any solutions to this absolute debacle yet? I looked through, and I have not found anything yet.


Yet another complete and UTTER screw-up by Microsoft if I may chime in.

Nikki Grace Holmes

(Zero relation to California's ex-governor.)

I have been FORWARDING the spam e-mails that were delivered to my mailbox, so if they were delivered to me, they amnday-well should be able to be sent off to Microsoft moderators, etc, for their review in my opinion. :facepalm:

@Limpgirl28   No, a solution was never determined.  If I use the web version of Outlook, the email is typically successfully delivered, so that has become my workaround.  Oddly, the one recipient it always seems to refuse is my wife's email. 


If I may ask, what exactly do you mean by "web version?"


All I do is use Firefox, log-in with the authenticator app, and now the e-mails I forward are not being delivered on the recipients' end. :facepalm:


Frustrating...absolutely frustrating. If the spam hits my inbox, I had better be able to send it off to them so they can block that kind of crap for other situations. That is ALL I am saying.


And proof of the spam e-m I get is right here.

Shoot, I am SUCH an idiot for forgetting to mention this part earlier. To report spam, DEFINITELY go here: