Method to email all users who have not posted in a thread

[Travis-Mc]

I have companies that sponsor product giveaways on one of my sites running vb 3.8.4. To enter the drawing, users just need to post in a thread. I promote the giveaway by sending an email through the admin control panel to all users and remind them to enter the drawing. A few users have commented about receiving the email after already entering the drawing. What I'm wondering is if anyone knows of good way to send the email to all of the users (who accept admin emails) except for the ones that have already posted in the giveaway thread. I thought I could create a new secondary usergroup, and either use a query to add everyone to it who has not posted in the thread, or add everyone first then use the query to remove the users who have posted in the thread. The problem is, I'm not that proficient with queries to make that happen. Does anyone have any ideas? Or can anyone help with the queries?

Thanks!

[Matthew Gordon]

You'd likely need a modification or at least a script to generate an email list. Try asking this over at vBulletin.org, our modifications site.

[Lats]

Try this...

SELECT
    user.username, user.email
FROM
    user
LEFT JOIN
    post
ON
    post.threadid = 888
AND
    user.userid = post.userid
WHERE
    post.userid IS NULL
ORDER BY
    user.username

Change threadid 888 to your theadid. This will give the username and email address of all users who did not post in the selected thread.

[Travis-Mc]

Thanks. That's a great start. Now what I need to add/change to get those users into a new user secondary group? That way I can just use the built in email in the admincp.