User Agent: Mozilla/5.0 (Windows NT 10.0; rv:65.0) Gecko/20100101 Firefox/65.0

Steps to reproduce:

first time connect to imap after a travel, 300+ emails to download for several accounts.

Actual results:

a) email headers are downloaded for all folders, then email bodies folder by folder.
b) even when all emails of a folder have been downloaded, selected messages cannot be displayed, I have to wait for all messages of all accounts to download before body is shown.

On a slow line (mobile), this gives a few minutes of waiting.

Expected results:

When all headers and bodies of a folder are downloaded, allow the display of messages in that folder. Alternatively, display the message already once its own body is downloaded.
This is probably somewhere between a bug and a feature request. In any case, it is a nuisance.

even when all emails of a folder have been downloaded, selected messages cannot be displayed, I have to wait for all messages of all accounts to download before body is shown.

This doesn't make sense to me unless you have some sort of performance issue, because a message which has been downloaded should be instantly displayable. Either that, or I don't understand your statement. Please clarify

Downloading: Folders A, B, C need to be appended. I see headers being downloaded and appearing in message list for A,B.C. While displaying message list of A).

Next, bodies are downloaded. Status line reports x of x message bodies have been downloaded for A (i.e. all). TB continues downloading bodies for folders B and C. During that time, I can select a message in the list of A, but its body does not appear below until all download actions on folders B and C are finished. As if downloading were sync and blocks everything.

The same happens in the morning when 300+ messages are downloaded for 5 accounts (much spam ...). TB is unusable until all messages, headers and bodies, did arrive.

consider a slow mobile line - so yes, there may be a performance issue involved. But on mobile, it is even worse if I cannot see the one important email while the spam is still being downloaded. (I could go offline and save mobile data once I see the important one)

The preferred action would be:
while downloading .... if message y is selected, stop general download, download message y, display message y, then continue general download. It doesn't seem to be like that for imap.

Gene, is it feasible to download newest message bodies first? It seems to me this would add significant complexity to autosync.

It has been requested for pop in Bug 385777 - pop retrieve most recent messages first (make order selectable)

I don't know if this can be changed easily (nothing is typically easy). Klaus, you might try disabling autosync. This should prevent downloading messages in folders you haven't yet clicked on. The way I think it works is that new headers are downloaded so you can see the new emails in the list. The full message bodies are downloaded in the background. But if you select a messages to read while body download is in progress, the transfer is "pseudo-interrupted" and the mail you want to read is downloaded (if it is not already downloaded) so you can see it right away.

To disable autosync set this false: mail.server.default.autosync_offline_stores and restart tb.

Do you always run on a "slow" network? How slow is it? If you run on a faster network, is there still a problem while downloading the 300 emails?

Klaus...

(In reply to gene smith from comment #4)

Do you always run on a "slow" network? How slow is it? If you run on a faster network, is there still a problem while downloading the 300 emails?

Adding to those questions:

• all imap accounts?
• any gmail?
• any server side filters?
• many (>40) Thunderbird filters?
• what happens if you remove status bar from the UI? view > toolbars > status bar

With answers to the above questions, we might be able to align your difficulty with one or more of these bugs https://mzl.la/3kUmjVR

not sure 78 or multiprocess has/will changed something.

In general TB is dead while downloading. If it is 300 mails per day (270 spam), that is 30 sec.

all imap, no gmail, no server filters, 7 TB filters. I don't really want to loose statusbar, I need it for Nostalgy++.

I set TB option 'don't sync at startup', otherwise I cannot start TB to have a quick lookup of an email - I would have to wait for sync first

(In reply to klaus from comment #6)

not sure 78 or multiprocess has/will changed something.

The current capabilities of multiprocess will not help

In general TB is dead while downloading. If it is 300 mails per day (270 spam), that is 30 sec.

For starters I would set the spam folder to NOT sync message bodies

all imap, no gmail, no server filters, 7 TB filters. I don't really want to loose statusbar, I need it for Nostalgy++.

Are any filters set to check message bodies?

I set TB option 'don't sync at startup', otherwise I cannot start TB to have a quick lookup of an email - I would have to wait for sync first

Is the current beta 93 better?

And, have you set your Windows antivirus software to exclude the Thunderbird profile?