licquorice, the link you provided does work, using the previous BTYahoo 'main' email address (my BTID email address is now different) - there is a 'Verification: Type The Code Shown Below' popup, and after the password revalidation screen, the BTYahoo 'Welcome to your account' page appears and the 'Manage Sub Accounts' link also works. Thanks.
Last year, after the BTYahoo email addresses were migrated to BTMail and before they were migrated back, I created some new BTMail email addresses (these are presently fine as I can send and receive emails). I have lost the ability to manage (add/delete/gift) the BTMail email addresses.
I've decided to wait until the BTYahoo addresses are remigrated to BTMail.
