I would suggest looking up some threads on here on how to manage spam and, more to the point, on how to manage/protect one's email addresses. THAT is the key.
I've used Mailwasher, in a business situation where we were getting up to 1000 spams per day and all I can say for it is that yes it will delete perhaps 99% of spam (if you put in the time to download and install about 50 filters of variously bizzare complexity, e.g. for detecting emails that contain font specifications within the Subject header) but it will also delete a load of real emails.
This kind of anti-spam technique is responsible for a lot of missing emails. In fact, email reliability is so poor nowadays
as a result of this technique that it is heading for being useless for important communications - especially with organisations which have a plonker of an IT manager.
Mailwasher is OK for identifying obvious p0rno emails but those emails stopped being obvious about 1 year ago. The share tip emails are much less obvious still.
I can easily write an email which Mailwasher will chuck out - you could try this very message
- on the basis of some word frequency rule.
The other day, I found some spam which was loaded with keywords that had obviously been harvested from my company's website. Now, that is really clever!!! We had to do a few changes...
Gertrude - presumably your ISP is now running mails past Spamcop or similar. This is OK but will also lose a load of emails. Loads of ISPs, especially certain foreign ones, get blacklisted en bloc.