I just purchased "SMTP Outbound Relay". I use "hMailServer" and setup SMTP to "relay" to relay.dynu.com with username relay@relay.superiorsoft.com and the password I created in the Dynu control panel when I first setup "Outbound relay".

I use hMailServer "Aliases" & "Distribution Lists" so that emails sent to some of my specific hMailServer accounts, "Aliases", & "Distribution Lists" are also sent to email addresses outside my domain, i.e. (Outlook.Live/hotmail).

Some external email services, like Outlook.live, uses the SpamHaus list to reject acceptin incoming emails from my ISP ip block.

I thought that the Dynu "SMTP Outbound Relay" service would resolve the Outlook.live/SpamHaus block, but the Dynu Outbound Relay service has not solved having these emails relayed at least how I have my hMailServer relay currently setup.

Plus, I have discovered that when I turn off hMailServer "relaying" inbound mail that gets forwarded to yahoo.com via the aliases & dist. lists, but outlook.live they do not.

But when I turn off hMailServer "relaying", at least YAHOO.COM gets them while Outlook.live/hotmail does not.

It looks to me like "relaying" prevenets all mail from being forwarded via alias or dist. list.

So one question I have is, could or do I have setup hMailServer relay wrong?
Is the Dynu relaying service "broken"?

Looking forward to you advice & assistence.

Thanks, Edward

I can't tell for sure about your case, but one thing is for sure: this SPF, DKIM, DMARC, etc stuff is, excuse me the expression, crap! It only makes things unnsecessary complicated. And it doesn't add anything to security or spam. Simply because there is always another way to do stuff. And paranoid as I am, I think these techs have been implemented just to keep private and small email providers away.

I am using hmailserver on my own box, using a dynamic "dynu.net" domain. I relay over my ISP's mailservers. Had been working well for a long time, until suddenly I couldn't send mail to gmail and outlook.com. No non-delivery, nothing. Emails just went up in smoke to these services. Other destinations worked well.

After ALOT of testing with this and that, the sollution was to add the following DNS record to my domain:
_dmarc.[mydomain.dynu.net] TXT v=DMARC1; p=none
Nothing more, nothing less. No DKIM, no SPF. Mails go through fine now. I haven't tested with Yahoo though (yet).

Would be nice if dynu.com staff could comment on this, and maybe verify this is the solution. Note that without such DNS record not even Dynu's "Full" email service can send to eg. gmail, even if using Dynu's webmail.