wiki-js/client/graph/admin/mail/mail-mutation-save-config.gql

mutation (
  $senderName: String!,
  $senderEmail: String!,
  $host: String!,
  $port: Int!,
  $secure: Boolean!,
  $verifySSL: Boolean!,
  $user: String!,
  $pass: String!,
  $useDKIM: Boolean!,
  $dkimDomainName: String!,
  $dkimKeySelector: String!,
  $dkimPrivateKey: String!
) {
  mail {
    updateConfig(
      senderName: $senderName,
      senderEmail: $senderEmail,
      host: $host,
      port: $port,
      secure: $secure,
      verifySSL: $verifySSL,
      user: $user,
      pass: $pass,
      useDKIM: $useDKIM,
      dkimDomainName: $dkimDomainName,
      dkimKeySelector: $dkimKeySelector,
      dkimPrivateKey: $dkimPrivateKey
    ) {
      responseResult {
        succeeded
        errorCode
        slug
        message
      }
    }
  }
}