Error in config, reported only as syntax error

I have a simple config (based on googling and copy paste) that contains an error, I don't know how to proceed.

I would like to forward all mails received to an smtp-server that requires username+password+TLS

The config:

listen on 0.0.0.0 port 25
action "relay" relay host "smtp://smtp.foo.bar" mail-from "@foo.bar"
match for any action "relay"

Apparently there is an error on line 2:

Oct 13 21:08:56 raspberrywood systemd[1]: Starting OpenSMTPD SMTP server...
Oct 13 21:08:56 raspberrywood smtpd[16986]: /etc/smtpd.conf:2: syntax error
Oct 13 21:08:56 raspberrywood smtpd[16986]: warn: no rules, nothing to do
Oct 13 21:08:56 raspberrywood systemd[1]: opensmtpd.service: Control process exited, code=exited, status=1/FAILURE
Oct 13 21:08:56 raspberrywood systemd[1]: opensmtpd.service: Failed with result 'exit-code'.
Oct 13 21:08:56 raspberrywood systemd[1]: Failed to start OpenSMTPD SMTP server.