Check Mail-Delivery-Process via "modern auth" (Microsoft Outlook)

Hello together,

currently I monitor our Mail-Delivery-Process towards Microsoft Outlook with the active-check “Check Email Delivery” (active_checks[“mail_loop”]). It uses IMAP as protocol, which is fine so far.

However, Microsoft will disable the access via IMAP on october 2022. This means IMAP won’t work for that specific use-case anymore.

Does somebody know a way to monitor this without IMAP? Microsoft says that they will rely on so called “modern auth” (authentification against Azure AD via token). But I am not sure which Checkmk-version is needed for that, as my Checkmk-site runs on version 1.2.8b9 (Enterprise).



Apart from the fact that you should upgrade for a thousand other reasons there is currently no code in checkmk to handle “modern auth” whatever that is.

Why is Microsoft deprecating IMAP?

This means OAuth against Azure-AD.
IMAP and POP are not deprecated but they need BasicAuth inside the Exchange Online environment.
The default config of an ExO setup is BasicAuth disabled.

@julien.kraka if you need only a mailbox for testing you can enable the BasicAuth only for a single mailbox. No need to change the complete configuration of you ExO environment.

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Yes I have a mail-address where its only purpose is the check.

When the BasicAuth is enabled for that specific address within ExO, do I have to adjust the check-parameters? “Mail receiving” is set on IMAP, and for “Authentication” I already have set username and password for the current check.

Seems like Basic Auth won’t be a viable option in the future, since they will base upon OAuth2. Any idea on how the check would work then?

Would be good if you can link to the official documentation where this is written. I found nothing about it.

Sure, here. It’s in german however:

EDIT: Found an english one: Deprecation of Basic authentication in Exchange Online | Microsoft Docs

Then you can read the documentation here

how to use OAuth with IMAP
Inside the mail_loop a change is needed to build the auth token and to sent it if you have a O365 account.

Do you know a Checkmk-version where that change for the mail_loop-Check is already implemented?
If not, I have to change the Check by myself and reconfigure it so it builds the auth token and send it?

following this question as i will have the same problem once Microsoft will stop sing the IMAP protocol.

do we have some progress on this? cause my mail on O365 stop responding when using check mail as of 4.10.2022.

Best regards,

+1 on this.

My IMAP checks against Ms Exchange Online also stopped working now since they use basic auth (username/password), and MS now has disabled it for our tenant.

A similar check that uses OAuth2 is much wanted.

I have the same problem for some customers.

There is a workaround to opt-out for the rest of the year. Microsoft will deactivate BasicAuth in January 2023!
Till then the Mail Loop Check either needs to get Modern Auth implemented or a new End2End Check just for ExO.

Here you can read about the workaround and all the other info:


Select IMAP and press Update
Wait for it to finish and then it should work again. I tested it and I can use the checks again. Remember that Microsoft will disable that workaround in January 2023!

@Sara is this on anybodys roadmap? The current plugin will stop working in 2 weeks for O365.

Hi, I checked with the devs. There is work being done on the OAuth and Exchange. Unfortunately, I do not yet have any estimates – I will let you know if I learn more about this.


Any news on this? I would really need this and its still not working in 2.1.0p19cee

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MS has begun the final shutdown phase and several tenants of ours cannot be monitored any longer with the existing check. Is there any work definitely planned to be done, and what’s the ETA? At the moment there is no way to monitor O365 mail delivery with Checkmk.

But why monitor it when it runs 365 days a year. :grin:

Hi! I am gathering information right now. As soon as I have more precise data, I will let you know here.
There is definitely work done about this – I just need to clarify the details.

Modern AUth support (OAuth2) is implemented in the Checkmk 2.2 version of the check. I asked if it can be backported. Which Checkmk version are you using?

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