Installed LM 1.8 and I like where this program is going. As I've had many problems with the SMTP bug in the past, I immediately went into admin.php and uncommented the SMTP debug.
Now I know you have tried hard to overcome the SMTP bug in your software, but I wish I could report that you have. I'm linking to screenshots after I tried running LM 1.8.
http://www.thinkingcap.ca/temp/lm1.8.gifhttp://www.thinkingcap.ca/temp/lm1.8-2.gif1. the first screenshot shows that I get a complete blank screen, no debug info period when running a mail out.
2.the second screenshot is the dreaded (and time consuming) SMTP bug. The email address that killed this email delivery is one I recognize, as I set up the account for this palvancouver.org site. The email address is forwarded to another email address on the site. There was no problem with palvancouver.org when I ran this email.
Surely if there is an expired email or non-active host your program can figure out to move on to the next recipient.