Function buildSimpleEmailMessage

apps/sim/tools/gmail/utils.ts:421–458

(params: {
  to: string
  cc?: string | null
  bcc?: string | null
  subject?: string | null
  body: string
  contentType?: 'text' | 'html'
  inReplyTo?: string
  references?: string
})

 * @returns Base64url encoded raw message
 */
export function buildSimpleEmailMessage(params: {
  to: string
  cc?: string | null
  bcc?: string | null
  subject?: string | null
  body: string
  contentType?: 'text' | 'html'
  inReplyTo?: string
  references?: string
}): string {
  const { to, cc, bcc, subject, body, contentType, inReplyTo, references } = params
  const boundary = generateBoundary()
  const { plain, html } = buildBodyAlternatives(body, contentType)

  const emailHeaders = ['MIME-Version: 1.0', `To: ${to}`]

  if (cc) {
    emailHeaders.push(`Cc: ${cc}`)
  }
  if (bcc) {
    emailHeaders.push(`Bcc: ${bcc}`)
  }

  emailHeaders.push(`Subject: ${encodeRfc2047(subject || '')}`)

  if (inReplyTo) {
    emailHeaders.push(`In-Reply-To: ${inReplyTo}`)
    const referencesChain = references ? `${references} ${inReplyTo}` : inReplyTo
    emailHeaders.push(`References: ${referencesChain}`)
  }

  emailHeaders.push(`Content-Type: multipart/alternative; boundary="${boundary}"`)
  emailHeaders.push('')
  emailHeaders.push(...renderAlternativeParts(plain, html, boundary))

  const email = emailHeaders.join('\n')
  return Buffer.from(email).toString('base64url')
}

/**
 * Build a MIME multipart message with optional attachments