Malware in attachment not detected

My wife received an email attachment that said it was a Xerox scanned image from a Workcenter. She happened to be expecting one, didn't notice this was coming from a bogus address, so she tried to open it. Her computer started locking up in various manners.
She forwarded it to me, I sent it to Virustotal where it was detected as infected. Results posted below. One of the detections is by Symantec.

I've restored her computer from an image. My question is why did the Norton email scanner (Norton IS 2013, signatures up to date) miss this on her computer and on mine. (mine receives email on port 110, the scanner should scan that attachment. ) And why did Norton not catch it when she clicked on it? Symantec detected it on Virustotal.

Thanks

~Virus Total results removed per Policy~