I\'m working with ruby on rails 2.3.4 and I yesterday I found out I cannot send emails any more.
The email-related credentials are ok because I could send emails until I
Based on the stack trace, it looks like you have a plugin action_mailer_tls that is not working with 2.3.4. You may be required to update that.
You may also want to upgrade to at least Rails 2.3.5 as that was current for some time, or Rails 2.3.8 which is the new current release. If you're going to invest the time to troubleshoot an upgrade, might as well kick it as far forward as you can.