postfix + mysql forwarding

Hi all, I have a postfix with mysql and courier that I set up a long time ago following https://library.linode.com/email/postfi … an-5-lenny">https://library.linode.com/email/postfix/courier-mysql-debian-5-lenny, which works fine. I've tried setting up forwarding as described here https://workaround.org/book/export/html/58 but it's not working, I suspect because I already have a 'real' inbox at the address I want to forward. It'll probably make more sense if I show you…

posftix config has:

virtualaliasmaps = proxy:mysql:/etc/postfix/mysql-virtualforwardings.cf, mysql:/etc/postfix/mysql-virtualemail2email.cf

the forwardings table in mysql has:

abuse@mysite.com dave@mysite.com

(etc. - all these local forwards have always worked fine)

dave@mysite.com dave@gmail.com (which I added today)

the users table has:

dave@mysite.com (password)

(etc.)

postmap -q abuse@mysite.com mysql:/etc/postfix/mysql-virtual_forwardings.cf returns dave@mysite.com (as you'd expect)

postmap -q dave@mysite.com mysql:/etc/postfix/mysql-virtual_forwardings.cf returns dave@gmail.com

…But emails are not being forwarded to dave@gmail.com.

Ideally I'd like emails to continue to be available via courier on my server but also be forwarded to dave@gmail.com. If not possible, I need to be able to continue to run postfix/courier as is for other accounts, but need dave@mysite.com forwarded to dave@gmail.com without too much upheval to the other accounts/setup I have on the box.

Much thanks in advance for any pointers.

Dave