we noticed for quite some time that nobody from our company receives the emails that are sent from EPD containing the FTP download links. So I recently opened a case with BMC support.
Just last week we finally found the issue: our ISP blocks mails that do not match "FCrDNS" (Forward Confirmed reverse DNS). Also many filters mark mails as spam when originating from incorrectly set up email hosts with no FCrDNS.
FCrDNS is considered a best practice in terms of internet based services, some RFCs also define it as a requirement for SMTP - RFC 1123 - Requirements for Internet Hosts - Application and Support , see sections 5.1 and 6.1.1
We discovered that the EPD mail server doesn't even resolve to a real DNS entry, therefore cannot be confirmed in that way and our ISP rejects those emails. No real DNS entry means that there is no record whatsoever that the sending SMTP host really belongs to the bmc.com domain. Basically this could also be done by setting up an SMTP server on a computer anywhere in the world and just sending mails with it containing a hostname claiming to be a member of the bmc.com domain.
Still BMC support told us they won't change that for the EPD mail servers. They told us to just whitelist the mails, but that's in the hands of our ISP. The funny thing is that other BMC mail servers match FCrDNS (we receive the mails from support, TKU updates, support notice, partner mails etc.). Just EPD seems to be different.
Anyway, I was wondering if there are more people or entire companies who encountered this but didn't bother to open cases with support. I honestly find it hard to believe that we seem to be one of the few companies that got that problem as FCrDNS seems to be used by many ISPs now to make sure that emails really originate from a legitimate source.
Thanks for any insights!
I have forwarded this to the relevant team to look into this issue.