email in junk folder?

As long as they get placed in the junk folder, ther is no problem. It's just that your e-mail address got harvested by those spammers.

If you use most web mail service, they have an adaptive junk filter. Same thing if you have a POP or EMAP account and use Thunderbird as your e-mail client.
If any show in your in box, just mark them as spam/junk. This will teach your junk filter that the message is junk. The filter do use signatures like inconcistent addresses, key expressions and some others.

Blocking the sender's address if useless as that address is ALWAYS false.

Yes, they can slow you down, especialy if you have a POP type service.

Electro
September 2012