Discourse will not accept forwarded email but successfully sends and an error message to the original sender?

AI-generated summary

exlabs encountered an issue where Discourse rejected forwarded emails from Microsoft 365, despite successfully sending an error notification to the original sender. The problem stemmed from the email being blindly forwarded to mycompany-category-1@discoursemail.com, which Discourse couldn’t process. supermathie clarified that the email must be addressed to a configured incoming email address, such as support@mycompany.com, rather than just being forwarded to a category address. After adding the support email to the ‘Custom incoming email address’ field, the issue was resolved. exlabs also noted that replies from Discourse were delayed by about 15 minutes, which supermathie explained was due to the email time window setting. The issue was resolved with the correct configuration and understanding of how incoming emails are processed in Discourse.

Hello everyone,

I am using the “Configure incoming email to create new topics” feature.

The workflow is like this:

  1. User sends email to “support@mycompany.com”
  2. Microsoft 365 forwards this email to “mycompany-category-1@discoursemail.com”
  3. New topic should appear.

But I am getting the error message of a REJECTED email in Discourse,

I think Microsoft 365 is not including all the information that Discourse needs in the header.

I trialed this using my personal email (Gmail) when it forwarded to discourse it worked first time! This seems something related to Microsoft 365.

The odd thing, the original sender does get an email from discourse notifying them of the error! So discourse does know who the original sender is.

I really do not know how to go forward with solving this issues, can anyone help?

Is support@mycompany.com configured in Discourse to accept mail, e.g. as a group inbox address or category address?

That part is crucial - Discourse does not see the SMTP envelope, only the mail itself. A blind forward to mycompany-category-1@discoursemail.com won’t be visible to Discourse.

Hi Michael,

Thanks for much the knowledgeable reply, I was worried that not too many people use this feature and I might just get tumbleweed.

It is using the category address only. We have a private category called “Support” and in the category settings it is configured like this,

Ok, that will only work if people are addressing (in to/cc) that address.

You need only add support@mycompany.com to “Custom incoming email address” and it should work.

The odd thing, I setup a Gmail account to forward to company-support-12@discoursemail.com and that worked! But changing over to our actual Microsoft 365 support email managed to break things, so I assumed the error was with Microsoft.

OK, I have added this to the box,

`mycompany+support-12@discoursemail.com|support@mycompany.com

I will active email forwarding, send a test email and see…

Will report back.

OK, adding our support email to the box fixed it! Thanks :clap: :smile:

However, when I reply from Discourse, is seems it never generates a reply email. I have checked in admin/email/sent and there is no record of Discourse doing anything. I have waited 10 minutes for it to arrive and nothing yet.

The reply email is sent after about 15 minutes when I reply using Discourse. Great it is working! Thanks

It was probably doing a “forward as attachment” rather than a blind forward.

You can adjust this to your liking by looking for the email time window site settings.

Thanks so much for all the help! This made my day.