Auto-forwarding to microsoft for a distribution list

[Wayne McHugh]

Something strange is happening for us, but I am not quite confident how to describe it - I may not yet be aware of all the possible elements, however ...

For historical reasons, our organisation domain is presented through Google non-profits, and therefore our organisational email addresses are also hosted through GMail.

More recently, Microsoft365 has become available to us for free (again, non-profit program), and so some of our organisational work is now done around Micrsoft365.

We wanted to create a few distribution list email addresses, and the Microsoft365 method is really clean for that, but the pathway had to be ...

1) Setup an email address on our domain, eg c...@domain.org.au, and setup a permanent auto-forward to c...@domain.onmicrosoft.com.

2) Setup c...@domain.onmicrosoft.com in Microsoft365, which is a distribution list, which has members to whom the email would get replicated.

It is messy but it has been working.  Until very recently.

Testing has shown that emails with attachments are not being sent through, but emails without attachments are going through.  So the workpath is still functional, but it breaks with attachments.

We've proven the email with attachment is reaching GMail, but we cannot trace whether the failure beyond that point is with GMail or Micrsoft365.

In GMail we have tried the for auto-forward option and setting up a rule where emails from all senders are forwarded.  They give the same result.

As I said, I'm not confident I have absolutely proven this happens from all senders, nor all attachments, but if anyone has insight into an issue that touches on what I've described, I'd love to hear.  I have exhausted independent inquiry paths available to me.