It seems my e-mail address may be compromised: when a third party e-mails my personal comcast address firstname.lastname@example.org, they will get a "permanent error" back immediately, stating that "delivery to the following recipients failed: Spainny2012@mail.com".
Should I be concerned, how do I rectify?
First, verify that the sneder is actually sending mail to your Comcast address.
From the info you gave, the sender is receiving an error for email addressed to Spainny2012@mail.com, not your Comcast address.
@NickjG0815 wrote: ... "delivery to the following recipients failed ...
Check your Auto Forward & Filter Rules settings under (gear icon) / Settings /
Mail / Auto Forward /
Mail / Filter Rules /
to make sure these have not been set to forward your mail to that address. If you need help, Comcast Security Assurance should be able to assist. Give them a call at 1-888-565-4329 (from http://constantguard.comcast.net/help/report-abuse/). Note that this is NOT one of the general customer service numbers. The first-line reps there are sometimes not very helpful, so you may need to be persistent and keep at them until you get a satisfactory answer.
I had exactly the same problem with the same (bogus) email address, email@example.com.
Just started yesterday.
The answer above is correct. In "Settings" on the web email site I found that auto forwarding had been enabled and that email address had appeared as the place to autoforward to. No idea how that happened. I deleted the address and unchecked the enable autoforwarding box.
Something strange going on with the xfinity email site.