I am also noticing similar behavior of this variable (I was going to post it in troubleshooting, but found it here with a search of the forum).  
If I preview {SERVER(IP)} in the Variables dialog, I get the hostname of the server (presumably the one defined in my client connection to the server, because it's a CName, and not a FQDN, at that).  But if I include it in an e-mail notification, it shows up in the e-mail as 0.0.0.0.  That's regardless of whether I run the job containing the notification as a "test" (manually from the client UI), or automatically on a schedule.
I want the e-mail notification to identify what server is sending it.  Upon further poking around, it seems {COMPUTER(Name)} does what I want (it gives the client's hostname when I view it in the Variables preview, but the server's hostname in the e-mail notification), but I'm still not at all clear on what {SERVER(IP)} is supposed to be.  I'm currently running 8.1.0 on the server and 8.0.0 on the client.
Thanks,
Rebeccah
                      Edited by user
                       
2016-06-06T23:30:30Z
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Reason: Not specified