* @return The value of found property. (NotNull: if not found, exception but basically no way)
     * @throws NumberFormatException When the property is not long.
     */
    Long getTimeAdjustTimeMillisAsLong();

    /**
     * Get the value for the key 'mail.send.mock'. <br>
     * The value is, e.g. true <br>
     * comment: Does it send mock mail? (true: no send actually, logging only)