I have largely achieved what I need to, but due to the way I've implemented it I'm finding that certain e-mail servers are refusing to accept our messages.
We have a mail-enabled Public Folder in Exchange 2013 to receive certain enquiries. We want people emailing to receive a reply saying "Thanks we've got your mail, we'll deal with it in due course" etc.
So my public folder is Enquiries and accepts emails addressed to email@example.com. I've used the Folder Assistant in Outlook to set up a reply template which sends the auto reply.
In addition I have added a new email address firstname.lastname@example.org to the public folder and set this as the default reply address.
Separately, certain users have SendAs permission for the public folder so they can send out replies without their own direct email address appearing.
All works ok except that we get rejections from certain email addresses and I'm 99% sure that is because their SMTP server is doing some advanced antispam checking and identifying that noreply.mydomain.com is not valid (which indeed it isn't).
What's the best way round this? Could I create some dummy MX record? If so, where should I point it?
Is there any way in Exchange to set the autoreply to come from a different address? That way I could setup a distribution group email@example.com (with no members) and have the reply sent from there.
Another way was to try and route outbound email to the problematic addresses via our ISP's smarthost, but it seems when creating a Send Connector I can only specify a domain as the address space and not an individual address.