Thunderbird and sent emails

[#1]

I'm sure this has been asked before but I can't find it.
I use webmail for everyday email but every now and then kick off thunderbird to archive my email.  This pulls down all the inbox stuff but how do I persuade it to also download the "sent" emails to the thunderbird "sent" folder.
Thanks in advance,

[#2]

In webmail put all the sent emails into the inbox, download them with Tbird. Sort by sender, select your messages and then simply move them to the sent folder in Tbird.

[#3]

Yeah, that would work.  I had hoped for a more elegant solution which would do a direct folder-to-folder transfer each time I started Tbird but clunky is better than non-existant.
Thanks.

[#4]

If that's Thunderbird 2 wouldn't setting up IMAP do the job?

[#5]

Actually it is thunderbird 12. 
IMAP is a possibility.  i've never used it - when I first started using email IMAP was new, experimental, poorly supported and flakey so I set my client up using POP and inertia has kept it the same ever since (despite changes of client and OS).  I'll have to investigate.
All these changes and new fangled inventions are so confusing...

[#6]

IMAP is the way to do it - it fully synchronises all the folders you see in Thunderbird with what you see in webmail. Just be aware that when you delete from webmail it will also disappear from Thunderbird, so the way to do it is as well as the synchronised folders in Thunderbird have a set of local folders; then drag and drop the emails you want to archive to the local folders. When you do that they will also disappear from webmail.