Gmail email addresses are allowed to contain as many periods as they want in the unique username field and gmail ignores them. Spammers/scammers have finally learned this and now keep using their accounts that would be filtered by blocked senders by adding periods to their usernames.
so
a spammer
vankathiru@gmail.com
is the same as
v.ank.athiru@gmail.com
or
v.a.n.k.a.t.h.i.r.u.@gmail.com
or
v.......a.n.k.a.t.h.i.r.u.@gmail.com
in Hotmail and most others these would be separate addresses, but not so with gmail.com
so can you please pass this on to the spam/phishing detect team that if the domain is gmail.com to strip the period characters out of the usernames when identifying reported spam/scammers by email address