Brad, are you by chance using a custom FriendlyURL provider? I've tested the notification emails in our test environment and they are all working as expected. We call a DNN method for building URLs, so Publish doesn't actually build out the URLs themselves.

Let me know if you have anything custom running there.

That was it!

My problem was that my portal alias was domainname.com,
but in IIS I am redirecting domainname.com to www.domainname.com

I changed the portal alias to www.domainname.com and the emails now working correctly.

I was having the same problem.  The portal was setup on domain.com and an Alias starting with "www." existed also.  The emails for Approval arrived looking exactly like the sample above, with the domain portion missing.

On closer examination I found that the "www." Alias ended with a "/".  Once I removed that trailing slash, and did another Submit for Approval, the email arrived with the http://domain... in place and the links all worked correctly.

So then I completely removed the "www." and tried it again. DNN worked and responded to the domain with and without the "www." - cool! - I didn't know that.  The bad news is the links stopped working again. 

So 3 things learned.  1) DNN doesn't need the extra Alias with the "www." in it when the portal is setup with just "domain.com".  2) For E:P Submit for Approval Links to work, you NEED to have the extra Alias with the "www.".  3) The "www." Alias won't work if you end it with a trailing slash (e.g. www.domain.com/.

I hope this helps someone else.  Without the clues in this forum thread above, I never would have figured this out - THANKS! - Jeremy