On a separate note,

I just noticed that I have a folder (under Profiles) called "Copy of xxxxxxxx.default". It's only 14 MB, but why would it be in my Profiles folder? Can / should I delete it?

Also curious:

I just now also unsubscribed from All Mail in "Account C", but that seemingly made no dent in my Profile size. (It's still holding at 88 GB.)

That account,is much smaller than the other two, only about 8000 emails, going back two years.

But is it also possible that there's something different in how the account is configured that is keeping it from using up my drive space, unlike Accounts A & B?

blue_sky said

Wayne Mery said

> On your new machine (and even on your current one), in Thunderbird you'll want to unsubscribe the All Mail folder for each account. Then memory usage for each account will drop by about half.

Eureka!

Per your suggestion, I unsubscribed from All Mail in "Account A", and (besides my memory usage decreasing, as shown in taskmanager) my TB profile size plummeted from 171 GB to 127 GB!

That's odd. I would not have expected your disk usage to go down at all. But then, the while situation is weird.

Anyone else, Thoughts??

blue_sky said

1. However, what I don't understand is, if All Mail is just an index, and doesn't really hold its own messages, why does it take up space on my local drive? 2. And secondly, What are other types of folders that are likely contributing to the bloated profile size, and which perhaps I should also unsubscribe from? (BTW, after the "Account A" All Mail unsubscribe, memory usage did fall by about half, roughly from ~ 400,000k to 225,000k. But after the "Account B" All Mail unsubscribe, memory usage is now showing at about 300,000k. Strange.)

2. none. The gmail All Mail folder is quite unique.

1. The answer is not straightforward. A. Today, if you were to define a gmail account to new Thunderbird profile, it make take some, or almost no space. It depends... B. Prior to version 17 (circa all 2012 iirc) gmail used at least double amount of disk space in Thunderbird profile, because of a downloaded message was kept in All Mail (if it was subscribed) plus every subscribed folder for which the message had a label. (reference http://kb.mozillazine.org/Gmail ) C. There is this rare, odd ball set of bugs or conditions where messages are redownloaded for some folders. For example https://bugzilla.mozilla.org/show_bug.cgi?id=816327

Case C is a triple or quadruple whammy because - the constant downloading hits CPU, the extra messages don't compact out, the folder index grows which increases memory, disk fragmentation increases, and iirc the amount of storage used by gloda/global search indexing increases.

"B. Prior to version 17 (circa all 2012 iirc) gmail used at least double amount of disk space in Thunderbird profile, because of a downloaded message was kept in All Mail"

So if I install TB on my new computer, and then configure my gmail accounts to it directly (instead of importing my old profile), is it likely that emails older than 2012 will reintroduce the same set of bugs as before?

Meaning, will TB's behavior now with Gmail accounts follow all current rules of behavior, or, will behaviors of older emails (e.g. expanding index and non-compacting messages), mirror their same behaviors (and bugs) as in the profile on my old machine?

If you are starting with a new profile the behavior is only dependent on Thunderbird. So the rules/behavior is per the version of Thunderbird you've installed