I don't have an answer (sorry) but I can say that you might not be doing anything wrong--I (and others, according to a couple of other threads I found here) am running into the same or a similar problem. I have had DKIM working correctly with a different mail server product, but I switched to SmarterMail about 2 weeks ago and haven't been able to get it working yet. I guess it's either a SmarterMail bug, or we're all overlooking an important setting somewhere.

OK think we figured this out.

 

DKIM was not working as seen in the message headers of emails sent to hotmail and yahoo mail.

 

After giving up on DKIM I spent some time setting up DMARC.

 

Now our DKIM is being recognized by Yahoo and Hotmail.  I don't understand this stuff well enough to say way.

 

In fact for the first time in awhile our messages actually did not land in the Yahoo spam folder.  

 

But Hotmail is still putting us in the spam filter.

 

 

Still having some problem with DKIM

 

We set it up in our DNS server, but when I look at the headers of email I send to Yahoo Mail , I see DKIM = neutral.

 

This is better than DKIM = fail.  But it still looks like spam.  We need to get a DKIM = pass response.  Not sure how to do that.

 

So for now we still can't send out our newsletters because they will go into spam folders.  I've spent hours on this.