I am just a user, the same as you, but I do not see the developers updating Thunderbird's addressbook to be a database of current, alternate, and old email addresses for individuals, marking which are active and which are not. My experience has been that, after entering a few characters, Thunderbird displays addresses that match the characters and then I made the decision, not Thunderbird. My suggestion to save the addresses but keep them away from the active addressbook, would be to do this:

1. create a new addressbook
2. move the old addresses to the new addressbook
3. export the addressbook to one of the options for backup
4. then, delete the newly-created addressbook.

You would now have saved all the addresses in case you use them again, but they won't show up in Thunderbird. A bit clunky, but it's a possibility. Good luck. :)

Yes, I could do that but that would make those addresses inaccessible to me from within TB which is not what I want (as I did say). You also don't address this issue that yes, most of the time TB fills in the address I want after a few letters so I get very used to accepting that particularly as it has the correct names, just the wrong address. That is a real pain as I either get a bounce message and have to resend, or sometimes I might not get a bounce message because the address technically still exists but the owner no longer uses it. (Yes, they shouldn't but people do.) I have some sympathy with the developers not wanting to overhaul the address book but the changes when TB went to storing addresses in sqlite databases were huge compared to this suggestion and the database structure that is now used seems to me to make the sorts of changes I am suggesting relatively easy. What you say also doesn't address this issue that, at least for me, the Email address TB fills in is not the one it usually does and is a dead address. I continue to believe that that's a bug.

I am not understanding why you would want an address book to contain invalid addresses. The only purpose of an address book is to contact the person, so keeping it fresh and containing current information is the priority.

What possible use does having the old address in a current address book have.

I have some sympathy with the developers not wanting to overhaul the address book but the changes when TB went to storing addresses in sqlite databases were huge compared to this suggestion and the database structure that is now used seems to me to make the sorts of changes I am suggesting relatively easy.

Just to put that in perspective it was more than 10 years in the making.

There are a number of bugs open to enhance the selection of address for autocomplete , these two appear to be closest to the discussion https://bugzilla.mozilla.org/show_bug.cgi?id=1939667 https://bugzilla.mozilla.org/show_bug.cgi?id=382415

Although this is also pertinent https://bugzilla.mozilla.org/show_bug.cgi?id=1058583

I see you are keen to strut your self-ascribed "blunt Aussie" identity: brilliantly played if largely useless for communication efficiency! I suspect your position goes with living confidently, largely in the present. I suspect I am not to the only one who finds that my addressbook holding old information, all to hand, all in one place without having to go to another program from one I use a huge amount of every day, is invaluable. Many of my contacts change Email addresses often, some are well into double figures for addresses now with say seven known dead addresses and three current. People also change partners, have children and often change jobs. I use the notes field to comment on the history. Being able to see all that in the one place and hence to search by their old addresses for things they may have sent me, or I sent them maybe 20 years ago really helps my life! Not your use of the addressbook: fair enough but I think software is for users as well as contributors (though many thanks for contributions!)

"10 years in the making": understood and maybe its structure makes thing possible that the contributors would never dream might be useful.

Thanks for the bugzilla links: some very old which I guess underlines that there are real issues here and, as you say, some will take a long time to fix. I was interested in the "popularity"/"ageing" discussion but wasn't clear where it all ended. Is there somewhere I can see what the current "under the hood" process is? I do think giving the user the ability to mark an address as dead would actually help those issues and without huge programming or CPU overload (though, yes, I accept it will need significant work).

However, what emerged for me from that is that I absolutely don't see the same address being offered every time: 9 times out of 10, 19 out of 20 perhaps but I unequivocally have had TB offering me ancient addresses for the same few initial letters typed in and that's been going through several versions of TB over at least a year. I _think_ it doesn't happen for all addresses as it seems to happen more often for some than others but that's hard to be absolutely sure is true. I am happy to file a bug report but as it's not replicable for me, and perhaps specific to me, I suspect it will just meet with your sort of "can't see the issue" response!! Persuade me otherwise oh confident Aussie boy!