I don't know. There seem to be quite a few different registries now. Do you log into any of the registries to change details? Maybe if you do that, you could log in regularly and check for new companies and change the options to email pretty much as soon as you buy the stock. I don't know how much that would help but you could try.
I have been noticing that some don't send out the new welcome letters if you're a day trader. It seems they only send them out if you hold for longer than a day or two.
As for the monthly chess ones, they're from a different source because they're linked to your HIN, not the stock's registry, but I haven't tried to change those. They might be easier to change, given it's only one organisation that does them..
None of that really helps. If you find anything useful out, please share.