Permanent failure delivering message to target recipient. Status set to 'failed' - Email

[Joshua T M]

Hi All,

We have started to receive Status set to 'failed' error messages relating to No MX records returned for domain: *DOMAIN*, mail delivery not possible when sending automated and manually generated emails from within Hornbill with direct send. This occurs (seemingly) at random but we have noticed that this issue has become progressively worse over the last week and we have not expeianced this prior.

I have attached extracts of the logs, the first is a sucessfully sent email, the second is a failiure. 

Could you please let me know if this is a common occurance? I am unable to find anything related to "Status set to 'failed'" via the Forum search.

 

[Keith Stevenson]

Josuha
Thanks for the post. Ive removed the attachments as they contain personal email addresses and this is an open forum.  The emails in the Failed Txt file failed dur to the recipient not existing on the given domain (hosted by MS) and when we try and deliver the email it returns the error  550 5.4.1 Recipient address rejected: Access denied.

This is a MS\Recipient problem and not a Hornbill problem  (We perform the lookup get the MS server as MX record, connect and try to delivery this as expected) 

We would suggest that you escalate this to the Domain Admin. 

Kind Regards

Keith Stevenson
 

[Joshua T M]

1 minute ago, Keith Stevenson said:

Josuha
Thanks for the post. Ive removed the attachments as they contain personal email addresses and this is an open forum.  The emails in the Failed Txt file failed dur to the recipient not existing on the given domain (hosted by MS) and when we try and deliver the email it returns the error  550 5.4.1 Recipient address rejected: Access denied.

This is a MS problem and not a Hornbill problem 

We would suggest that you escalate this to the Domain Admin. 

Kind Regards

Keith Stevenson
 

Thanks Keith,

As per the other txt file, after failiure and resending it sucessfully sends so the recipient does indeed exist and your platform then detects this, the issue is intermitent. Can you please take a deeper look into the issue? 

This is occuring across multiple domains.

[Keith Stevenson]

Joshua, 
Thanks for the post. 

The Hornbill mail client will do the same every single time we send an email via direct outbound.  The rejection message stated is direct from MS (in this case). We have no control over this.  The fact that the email address isnt valid and then is would need to be investigated by the owner of that domain in collaboration with MS. 

That said.. We have watched your traffic for a while and some DNS Probes for NX Lookup do return 0 (This is different to the specifc 550  error above which is still an MS Issue. ) - This appears to be due to a Cloudflare issue and intermittent. Which may explain why you see some emails fail to resolve domains and then work next pass. 

This can be seen by doing 

nslookup 
server 1.1.1.1 

set querytype=mx

siwfinc.com

if you run that several times you will get a timeout on 1 or more and the next time this is fine 

if you change the domain to hornbill.com it seems to be fine and if you change server to 8.8.8.8 (googles) its also fine. 

So it appears that you are seeing 2 different issues (1 hard failure - 550 which is the MS issue) and 1 intermittent and merging the two. These are 2 distinct and seperate errors. 


Kind Regards

Keith Stevenson