I use Thunderbird to filter a lot of spams, and it works pretty well.. but I still see
several spams go through every day.

spam count on my personal email for past 7-8 months is about
14k (11450+2654)

On the mail server, there is no spam filter at the moment, but in past
I used to have DNSBL (Spamcop and few others) blocking. Thinking
about putting it back on.