SendGrid metadata and RailsWritten August 7, 2012. Tagged SendGrid, Ruby on Rails, Action Mailer. We have a Rails app that sends its mail through SendGrid. SendGrid lets you specify metadata in your mail headers, which you can put to excellent use. The activity logSendGrid's highly useful activity log (docs) lists the last week of sent mail. Not the full mail, but the recipient e-mail address, the

