Ajax error sending newsletter

I am using simplenews, phpmailer and mimemail for mailing on my drupal sites.

I was using SMTP and switched to phpmailer due to a error that was sending out blank email bodies and erroring out the entire newsletter send. After a lot of research and finding other issues with the SMTP module, I decided to see if the phpmailer module would work any better, but now I have new errors and still no newsletter getting sent out.

I am not sure at this point if I have an error with either of the modules above... but I figured I would start here.

After changing to phpmailer and updating all of the settings, I tried sending the newsletter again and it said that it had sent the first 300 messages, but never sent any on cron, nor did anyone actually receive any emails.

I turned off cron and got the error that the "from address" had a syntax error. It had the site name listed, which is obviously not the email address, so I went back and changed those "from" fields to be blank so they would default to the site name. It still gave me the same error, that the from line was not working.

I'm honestly at my wits end. We've been trying to send out this newsletter for three weeks and I have searched Google up one side and down the other, looking here, at Stack Overflow, on random blogs -- anywhere to see if I can find the solution to this.

The error is in the attachment. I really appreciate any insight or suggestions as to how to resolve this. I really am just at my wits end and don't know what else to try next :(

Thank you for taking pity on me!