In response to Drauk, what appears to happen is that the only email address on my account that seems to be collected or "farmed", is the old original "prime" account address. Although I no longer use it, all of the spam seems to go there rather than the address that I am using to access Pprune now. (But yes, I do still have to empty the cesspit every week or two) It did confuse me why this should be so, but it does work and I ain't knocking it :-)
best regards to all,
CTL.