Sending emails with Hermes

In an effort to maintain consistency across our emails, please following the following guidelines:

1. Abort all repeating emails that do not have an unsubscribeToken in the email's TemplateModel
2. All email TemplateModels should have the following data shape:

{
  to: string!,
  subject: string!,
  preheader: string!,
  recipient: {
    username: string!
  },
  unsubscribeToken: string,
  data: mixed
}

To break down these fields:

to => the recipient's email address subject => always calculate subject strings inside of Hermes for consistency, even if it is a static string preheader => represents the "email preview" that gets displayed in email clients and push notifications. The content of this string is meant to draw users into the email, but will not be displayed in the email body itself recipient => contains user data about the person receiving the email. The only field that is absolutely required is the username field. If a username field does not exist for the recipient, the email should always be aborted. The username is used to link to the user's notification preferences, and if it doesn't exist they have no way to change their preferences. unsubscribeToken => this is a required field for all repeating emails. A repeating email is one that a user might receive regularly based on actions taken by others on Spectrum. Examples include: new direct message notifications, new thread notifications. The unsubscribeToken is not required for non-repeating emails, which should be one-off emails like receipts, community invitations, email validations, etc. data => can contain any abstract data needed for the email to render its body content.