United Wifi and MITM attacks on TLS

So, I was going to check my Email to my private IMAPS (TLS, port 993) mail server. And I get this warning about the certificate from my mail client (Apple Mail). Curious, I checked the certificate, and found this:

Server certificate
subject=/C=US/ST=Colorado/L=Arvada/O=Ogre/CN=*.ogre.com/emailAddress=leif@ogre.com
issuer=/C=  /ST=Some-State/O=Blue Coat SG900 Series/OU=4312240020/CN=172.16.0.50
Now, this doesn't make a whole lot of sense. I know my certificate was not issued by this issuer. Who is that ? Well, Blue Coat SG900 is obviously a proxy of some sort, presumably a transparent (captive) proxy. But why would United care about my IMAP over TLS connection? What could they possible want to see? My email? Anti-virus? And, this is after I had paid the $8.99 (very reasonable) internet fees (so it should IMO not be captive any more).
 
Needless to say, I did not trust this certificate / MITM attack and therefore, unable to check my email. Very lame.

 

Note: This is the TLS handshake with the MITM proxy server:

Server certificate
subject=/C=US/ST=Colorado/L=Arvada/O=Ogre/CN=*.ogre.com/emailAddress=leif@ogre.com
issuer=/C=  /ST=Some-State/O=Blue Coat SG900 Series/OU=4312240020/CN=172.16.0.50
---
No client certificate CA names sent
---
SSL handshake has read 1754 bytes and written 456 bytes
---
New, TLSv1/SSLv3, Cipher is DHE-RSA-AES256-SHA
Server public key is 2048 bit
Secure Renegotiation IS supported
Compression: NONE
Expansion: NONE
SSL-Session:
    Protocol  : TLSv1
    Cipher    : DHE-RSA-AES256-SHA
    Session-ID: XYZ
    Session-ID-ctx:
    Master-Key: XYZ
    Key-Arg   : None
    Start Time: 1397924326
    Timeout   : 300 (sec)
    Verify return code: 21 (unable to verify the first certificate)

Hacking: