Sub Domains and DNS MX records

I am not great with DNS but bear with me and see if you have any ideas. We have an ERP system. it has the ability to have emails sent directly into jobs via email. So we have two domains mx records setup.

  1. Our main domain company.aero forwards to O365 with no problems whatsoever. We send/receive all of our emails with zero issues.
  2. The second is a subdomain erp.company.aero that is use purely for said ERP system email sends from that email address with no problems as it should…BUT…it only receives email IF the email is coming from another O365 sender. So when a customer (who is NOT using O365) gets an email from a staff member, CCing the job (jNNNNN@erp.company.aero) and they reply to it…the staff member gets the reply but the jNNNN@erp.company.aero gets rejected as not having a valid MX record. Testing does exactly the same…I send from my O365 account, it gets there…I send from my GMAIL account, it gets rejected.

" Your message wasn’t delivered to jNNNNN@erp.company.aero because the domain erp.company.aero couldn’t be found. Check for typos or unnecessary spaces and try again."

DNS Configuration is

Any thoughts? Ideas? HEEEEELLLLPPPP!!! :slight_smile:

Hi, @Aussie_Steve. I have no idea as we don’t provide the email service for your domain.

I do see the domain (because I’m on the support team) even though you didn’t tell us what it is publicly. I can see the domain is using Netlify DNS.

Now, we can help you troubleshoot the DNS service itself. For example, we can answer questions like these:

  • Questions about how to make DNS records with Netlify DNS.
  • Questions about existing DNS records not working.
  • Questions about how to migrate to our DNS service.

However, you are not asking about the DNS service. You are asking about the email service and I have no way to examine or troubleshoot that. I simply don’t have access to any of the information you require because we don’t control your email systems in any way.

I strongly recommend contacting the technical support for your email service about this. They should have more information.

You are still welcome to ask this question here but the support forum for your email service would likely yield better results.

The mail service is claiming that the MX record is not valid.

"DNS type ‘mx’ lookup of erp.company.aero had no relevant answers.

That, to me, is a DNS issue. I could be wrong…I am no expert in this area either, but that is the advice I’ve gotten.

Hi, @Aussie_Steve. You are 100% correct. If the DNS record itself is not working (and it wasn’t) that is a DNS issue and our support team definitely can and will always help with that.

I’ve gotten that fixed now. If you see this happen again there is a way to fix it without the support team’s assistance - which is to delete and recreate the non-working DNS record.

​Please let us know if there are any questions or if there are any other DNS records not working correctly.

Working now…Many Thanks

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