Syntax for Trash and Sent on new imap account

Hi,

I'm trying to configure WL for a new imap account (startmail.com).  Everything
works as expected, except I can't figure out the syntax for their Sent and Trash
folders for my .folders file.

For instance, with Gmail you say

	%[Gmail]/Sent Mail:user/[email protected]:993! 				"Sent"
	%[Gmail]/Trash:user/[email protected]:993!					"Trash"

For another imap (exchange) account, I have

	%Sent Items:user/clear@server:993!									"Sent"
	%Deleted Items:user/clear@server:993!								"Trash"

For the new account, all I have is webmail access, and there I can see their
"Sent" and "Trash" folders.  But when I try various alternatives for connecting
to them, WL creates new folders with these names, rather than using the ones I
want.

Am I overlooking something?  How can I figure out the syntax?  I thought I'd ask
here before writing to their support, as I don't think they know anything about
WL.

All the best,
Greg