I'm afraid the Tools > Mail Merge Wizard has never been one of my favorites. Too complicated.
I always train people to just "roll their own" when making a mail merge document.
Everything you can do in the mail merge wizard, you can pretty much do in the roll-your-own approach, especially since you can now print all documents to a single file and then open that and customize it as you like, before printing on paper.
and viewing/editing the file output. (Click to see the bigger version; you'll see different values in the two letters.)
BUTOne thing you can't do in the roll-your-own approach is do an email mail merge.
Do you really want to go through the complexity and muscle aches of using the Mail Merge Wizard? No. And you don't have to. You're going to mix and match.
Step 1. Create your email the way you want it with the roll-your-own approach.
Save it. Keep it open.
Step 2: Set up email configuration. In Writer, choose Tools > Options > OpenOffice.org Writer > Email. This setup worked for me. Key settings are smtp.comcast.net and port 587. You just need to do this once. If you have security on your email, like requiring a password to send, you'll have to click the Server Authentication button and enter additional information.
Step 3: Choose Tools > Mail Merge Wizard. Choose Current Document, or else browse to your document, and click Next.
Choose Email and click Next.
Select the database you're using and the table. Click OK and click Next.
Keep clicking next til you're here. Fill it in by selecting the field from the database that has the emails in it, and anything else you want. Click Send Documents.
You'll see the progress window (in this test I only sent two emails).
And you're done!
The received email looks like this. Note that I sent it in email format, but with the extra carriage returns I put between the lines in Writer, it looks a little spacey here. You'll want to experiment with and adjust how you format the original Writer documents and what format you send in.