I've had the email address hdewitt@onetel.com since 2002 or so. Since then I believe onetel has been taken over by Talk Talk. For a while Talk Talk continued to support legacy email accounts, but they have finally decided to discontinue them. That is, I thought I had managed to confirm the account with them, but now I can't log into it, so it looks as though it has been discontinued.
Unfortunately the onetel email address was the one connected to my PayPal donation button. That is, in 2007 or so PayPal provided code for a donation button, which I installed in the sidebar, and the email address I was then using with Paypal was the onetel address. PayPal later changed the button to a Buy Now button without notification, because they'd changed the rules: you could only use a donation button if you submitted a form stating that you were a nonprofit. But I'm not a nonprofit, so I couldn't provide the form. The button was simply a mechanism for people who had, as it might be, bought a secondhand copy elsewhere and decided out of the goodness of their hearts to send a gift to the author. The new button rather bizarrely sent them through to an invoice for Samurai Secondhand Sales; this must have been pretty baffling, though some have persevered despite the peculiar interface. Now the PayPal button has reverted to a Donate button, but they have disconnected it altogether.
At any rate, I can't insert a new button, with a functioning email address, because of PayPal's requirement for nonprofit status. So I'm inserting a link to my Ko-fi account instead. Payments from Ko-fi are still processed by PayPal, so it's a pretty clunky workaround, but at least this does sidestep PayPal's weird requirements, as well as the problem of the obsolete email address.
Ko-fi can be found here:
https://ko-fi.com/dewitt
Thank you very much to everyone who has kindly sent donations over the years.