Thunderbird is very slow if it has not been used for a long time.
I use Thunderbird on several computers and my IMAP account contains several hundred thousand emails.
In everyday use on my main computer this works very well and I have no problems with the speed of Thunderbird. If I open Thunderbird on a computer that I only use every 2-3 weeks, it becomes a real test of patience.
Thunderbird updates, indexes and compresses about 50 folders in the background.
As a result, Thunderbird is hardly usable for about 30 minutes. For example, if you want to write a new email (the most common case), the mail editor is extremely slow to use - characters entered only appear with a delay of 10-30 seconds, even though the computer is already very powerful with an SSD and a fast CPU.
Is there a configuration option to run the mailbox update with such a low priority or to assign a high priority to the Mail Editor?
ప్రత్యుత్తరాలన్నీ (3)
my IMAP account contains several hundred thousand emails.
Are you saying you've accumulated 'several hundred thousand emails' in Inbox?
Yes :-) I subscribed to 2 dozens of mailing-lists over the last years :-) From my point of view a 30 minute blocked Thunderbird UI due to background indexing processes is not a good idea from a usability perspective. But its okay that the completion of indexing takes its time.
Two possibilities: turn off global indexing in settings>general and adjust sync in account settings>synchronization&storage.