I am recieving a security notification from my Bitdefender security program, need to stop firefox form establising a connection.

My virus program is sedning me this message. firefox.exe attempted to establish a connection relying on an unmatching security certificate to email.squarespace.info. We blocked the connection to keep your data safe since the used certificate was issued for a different web address than the targeted one. How do I stop firefox from contunally reaching out to this web site.