If you have subscribed via a gmail.com address to the mailing list in the format of user+tag@gmail.com, You're ok, but I had to block all gmail addresses that contain a plus sign, it was being abused, 1000's of emails were being added and used to target specific gmail users so their email would stop working because we were flooding them with subscribe confirmation emails.  It was a total of three target addresses coming from 1000's of different IP addresses.