How to download only recent mails in Thunderbird?

In the "Tools -> Account Settings", there's a setting in "Synchronization and Storage" to only synchronize the newest mail by days, weeks, months, size... This might be what you are looking for.

No, it seems that Tbird has a BIG shortcoming in that it does not let you download "only messages newer than x days". We have the option to not download "messages larger than", so why no option to not download "mesages older than" ?

It is a big problem that developers ought to address.

So many people take their email on several different devices. Thunderbird makes everyone download ALL their email onto EACH device, which is ludicrous. I use PCs in different offices, and never need to download more than my currently active threads, so would really like to be able just to download emails "not older than 14 days".

I have emails going back over 10 years. All need to be stored on the webmail computer, but in no way do they all need to be downloaded by Tbird each time I use a new computer