WGU started using GMail some time last year so the post below will no longer work. You can set up your WGU GMail account on your smart phone or other device by using your WGU email address and the regular settings for GMail. I hope this clears up some of the confusion.
I have copied this information about accessing your WGU email outside of the WGU Student Portal from a thread on the the WGU Student Hall.
The following information is a quote by WGU Student Hall user Keith:
For what it's worth, I use SMTP and POP (not IMAP) to access my WGU mail, via Outlook. It's just set up as another "POP" style account.
Incoming mail server: mymail.wgu.edu.
Outgoing mail server: mymail.wgu.edu.
The port settings are standard (110 for POP, 25 for SMTP).
Your user name is just your base name (NOT with the @my.wgu.edu at the end).
You can also use IMAP, but I like to actually pull all my mail from my various accounts down to MY machine, for archival and offline purposes.
As has already been pointed out, if you're having trouble accessing the mymail.wgu.edu server, it could be a restriction put in place by your ISP, to only allow port 25 traffic to go through your ISP's mail server. This shouldn't prevent you from GETTING your WGU mail, though. It's very unlikely that any ISP would be goofy enough to block port 110 (POP) traffic.
I've tried the above with my GMail account and it works great. You have to use the "import mail" function within GMail to make it work. If anyone wants the details or a walk through just let me know. Cheers!