无法通过Paperclip将存储在S3上的文件添加为ActionMailer中的附件

I'm using Paperclip and S3 for file upload and storage in a Rails 3 app. The uploading of the files is working well, but when trying to attach an uploaded file to an email message with actionmailer, I am running into issues. After a lot of troubleshooting, hopefully someone can offer a hint.I'm using Paperclip and S3 for file upload and