“I am totally ready to go through all my Internet based connections, personal, financial and otherwise, and provide each one with the necessary new Emil address(es) when the time comes.”
no need ... keep your old email service for a while and have it forward email to your new email address and at the same time send an auto-response email back to all senders that explains they should use your new email address in the future, that feature is called a “vacation” response, but it can be used for any purpose ...
also, POP is obsolete, instead you want to switch tbird to using IMAP, like POP, IMAP can load physical copies of your received emails to your PC plus maintain copies on the email server, but IMAP also will keep all devices you might use for email synchronized to the server ...
No on keeping my current Email and having it forward to a new one. I want 100% of my Email business removed from Verizon/AOL, at once, permanently. I will go through the work of informing all my personal contacts and changing the Email address in my profiles with banks, credit cards, vendors & clients, subscriptions, utilities, ect. That large task is just time consuming but not more than that.
No POP3 is not obsolete and the advantage security wise is with the proper POP setup parameters made the Email you get (bring into your Thunderbird Email client app) is deleted, not left sitting there, on your Email service providers servers.
IMAP is nothing more than an image/copy of what is sitting on your Email service providers system, thats all - its a mirror. Moving things to “trash” on your desktop just mirror-like moves them to trash on your service providers system, but there they still exist; as are all other Email changes you made - all ON THEIR SERVERS and mirrored to your PC. With POP I leave NOTHING on their servers; and I hjave no need to. And with Thunderbird properly profiled on both my PC and my Laptop, and with the Thunderbird data all on one USB remote data device, and always backed up, I can have the same Email files on either computer as I need, have no large and very little storage demands at the Email service providers end. No. IMAP is not only not obsolete, I have zero need for it.