I'm trying to use mutt to send the company's invoices. mutt will send them ok using the Zimbra server but it won't save the sent messages to the Sent folder.

The .muttrc file is as follows

set from=facturacion@unitan.net
set realname="Unitan SAICA - Facturación"
set folder=imap://mail.unitan.net/
set spoolfile=imap://mail.unitan.net/INBOX
set record=imap://mail.unitan.net/Sent
set postponed=imap://mail.unitan.net/Drafts
set imap_user=facturacion
set imap_pass=somepass
set header_cache=~/.mutt/cache/headers
set message_cachedir=~/.mutt/cache/bodies
set certificate_file=~/.mutt/certificates
set smtp_url=smtp://mail.unitan.net/
set smtp_pass=somepass
Thank you in advance for any help you can give,