I use Thunderbird and find that spam comes in waves. I'll get a smattering of spam emails in my inbox, flag them as such, and the number tapers toward zero. The

I use Thunderbird and find that spam comes in waves. I'll get a smattering of spam emails in my inbox, flag them as such, and the number tapers toward zero. Then, a month or two later, another smattering will appear, after the spammers realize the filters have adapted and change the composition of their spam emails.