a Google search returns multiple results for the main
issue of your concern; your emails being bounced or landing in spam folders.
https://www.google.com/search?q=phpmailer+2.0+spam+folderSome reasons your mail can get marked spam:
You're sending spam
Your IP, or a block of IPs surrounding your IP has been marked as a spam source on one or more blackhole lists
The content of the email is triggering spam filters.
The recipient has added you to their blacklist
The recipient didn't add you to their whitelist
You're sending a mixed source mail ("From: xyz@example.com", but sending it from "someotherdomain.net")
SPF records for your server are misconfigured/not configured at all
Domain keys are misconfigured/not configured at all
etc...
PHPMailer is a tool. Consider it a hammer. The hammer may have bent the nail, but only because the wielder didn't aim right.
The only way you'll solve this problem is by examining the bounce messages (if any), and whatever showed up in the recipient's mailbox. If they receive the mail, but it goes into a spam folder, then get a copy of the mail and examine its headers. Most spam filters will put their spam score/reasoning in there.
source:
https://stackoverflow.com/questions/6567213/phpmailer-sends-to-junk-email
