Odd E-Mail Notification from Norton Community

I received an unusual notification from the Norton Community last Thursday (30-Jul-2015) and was wondering if anyone had received a similar e-mail.

The "To" header was addressed to the e-mail address I now use for Single Sign On logins for my Norton account (i.e., not to the normal "lmacri <e-mail address>" that includes my community username) and the body of the e-mail was empty.  The subject line was "[Norton Community] New comment on Norton Internet Security forced update fails to activate" but there hasn't been any activity in the thread Norton Internet Security forced update fails to activate since 10-July-2015.

I looked at the properties of the e-mail and can't see anything overtly suspicious (e.g., the Sender is "noreply @ nortoncommunity.symantec.com" and Received From is "mail2.connect.symantec.com ([65.61.136.219]) by COL004-MC5F19.hotmail.com over TLS secured channel...") but I'm a bit paranoid these days.  I reported that unknown users were using the activation seats for my NIS product key in my Norton account shortly after Single Sign On was introduced (see my post in the thread Forum Login Linked with Norton Account Login) but Symantec told me that "your account history didn't show any malfeasance" and did not issue me a new product key.
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32-bit Vista Home Premium SP2 * Firefox 39.0 * NIS 2014 v. 21.7.0.11 * MBAM Premium 2.1.8