Thank you
Thanks for your helpful comments.
Gertrude
The most likely culprit is McAfee. I'll experiment with that.
Opfix,
the BT spamfilter is good, in my experience. However, I do go to the website routinely to check for wrongly trapped mail.
If I took up all the (spam) offers for extended private parts, my inside leg of 33" would not be enough...............
Para - Thanks for your ideas. I've looked at that site. I'll go back when I've got a bit more time.