Email Subscribers

Over the past several weeks I have had new subscribers trickling in to the tune of about 4 a day. Each has an email that looks legit (e.g. @gmail.com or @yahoo.com) but in the column that should show “name” there is always a code such as 5a4ebed83b849. How do I know if these are real subscribers? I have email subscribers sent to “single opt in”. Should I change the settings? I am concerned because I expect to start posting after a period of silence and I don’t want to do something that causes the site harm (I mean like if these are all spam). I note this happened at about the same time that I started getting spam email to my mollytierney.com email account. Thanks, m

The page I need help with: [log in to see the link]