The "go back to old version" option under Account Info does not restore the functions of the old version.
In the first place, the information given in "help" was not accurate, as far as I could tell. I couldn't find Steps 3 and 4 as described in the directions, in which I would be asked for my reasons for wanting to switch back to the old version.
Nothing happened until I clicked "Go". As soon as I did that, the dialogue box closed and my screen went back to my Inbox.
Although I'm supposedly in the old version, I still can't fill in the bcc list of recipients to an email directly from a sub-list in my Contacts. I guess I'll have to PRINT OUT my separate lists, and enter each recipient by hand.
Yahoo, please bring the old mail system back. You are pushing me closer and closer to opening a Gmail account.
Incidentally, I don't believe the explanation you give about why you got rid of the old system -- that many computers no longer support it. True, I had an occasional slow-to-load problem -- but it worked 1000% better than this one, up to the day you dismantled it.
Also, your explanation of the "advanced options" of the new Yahoo is so vague that I have no way of knowing whether it will do what I need. And the fact that once I try it, I won't be able to go back, makes it very risky.
I am trying to be civil, and to point out specific issues and functions in my comments. I would appreciate it if you would address these.