Out of Office Replies not being Delivered

Question

I have added DKIM records to our domain's DNS records and tested these using MXtoolbox. I followed the instructions in the Microsoft help on how to set DKIM records and DKIM signing up. I took the values for the CNAME records from Microsoft defender email authentication settings. I have set OOF on for website@ourdomain and sent a message from my @yahoo.co.uk email to website@ourdomain. I din't receive an OOF

I did a message trace in Exhange admin and there were 2 outgoing automatic reply messages from the website address to my personal address.

The first had status of FAILED and an event that is 'drop' and a reason: {(LED=250 2.1.5 RESOLVER.OOF.IntToExt; handled internal OOF to external recipient);(MSG=);(FQDN=);(IP=);(LRT=)}

The second has status of PENDING and an event that is 'defer' and reason: {(LED=452 this message has been deferred because the sender is sending too much mail for its authentication status. Please set up DKIM aligned to the FROM domain. See ........

(MSG=);(FQDN=mx-eu,mail.am0.yahoodns.net);(IP=188.125.72.73);(OutboundProxyTargetIP=188.125.72.73. OutboundProxyTargetHostName=mx-eu,mail.am0.yahoodns.net )}

Please can someone give me some idea of what to try next.

thank you

Alison Leah

Answer 1

Hi, @Alison Leah

The error message tracking message you provided may be due to the following reasons:

1.The first message trace shows that the OOF message is dropped because it is an internal OOF to an external recipient. This is a common problem when the OOF setting is not configured to allow external replies. You may need to check the OOF settings in the Exchange admin center to ensure that external OOF replies are enabled.

Also, be aware of the OOF reply type set on the remote domain, which will also affect the delivery of the OOF. Specifically, it can be seen Understand and troubleshoot Out of Office (OOF) replies - Exchange | Microsoft Learn

Understand and troubleshoot Out of Office (OOF) replies - Exchange | Microsoft Learn

2.The second message trace shows that the message was delayed because the sender sent too many messages beyond their authentication status. Identity authentication for outbound emails is critical, and you need to check that DKIM is being added correctly, which means that the domain in the DKIM signature should match the domain in the FROM address of the email. It can be seen How to use DKIM for email in your custom domain - Microsoft Defender for Office 365 | Microsoft Learn

Authenticate Outbound Email to Improve Deliverability | Microsoft Community Hub

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