How to access multiple customers with the dropdown in selenium webdriver Python

Question

How to access multiple customers with the dropdown menu by choosing one customer at a time(select_by_visible_text('Customer1', 'Customer2', Customer3) and clicking the send email button with an interval of 3 seconds for each customer?

In dropdown site:

    <select name="customer_id" class="customer_id" style="width: 200px">
    <option value></option>
    <option value=="164">Customer1</option>
    <option value="185">Customer2</option>
    <option value="80">Customer3</option>
    <option value="259">Customer4</option>

    Choose Customer1 in dropdown
    Insert email
    Click on the Button_Send
    Wait 3 second time

    Choose Customer2
    Insert email
    Click on the Button_Send
    Wait 3 second time

    Choose Customer3
    Insert email
    Click on the Button_Send
    Wait 3 second time

    Choose Customer4
    Insert email
    Click on the Button_Send
    Wait 3 second time

    from selenium import webdriver
    from selenium.webdriver.support.select import Select
    from selenium.webdriver.common.by import By
    import time
    navegador = webdriver.Chrome()
    url = 'www.testblablabla34572211.com'
    email = '[email protected]'

    navegador.get(url)
    time.sleep(2)
    navegador.refresh()
    time.sleep(2)

    dropdownField = navegador.find_element(By.NAME,('customer_id'))
    select = Select(dropdownField)
    options = select.select_by_visible_text('Customer1')
    options = select.select_by_visible_text('Customer2')
    options = select.select_by_visible_text('Customer3')

    #Select Customers
    dropdownField = browser.find_element(By.NAME,('customer_id'))
    select = Select(dropdownField)
    select.select_by_visible_text('Customer1')
    time.sleep(1)

    # Click on the Email field:
    browser.find_element(By.ID,'email').click()
    time.sleep(1)

    # Insert email
    browser.find_element(By.ID,'email').send_keys(email)
    time.sleep(1)

    # Click the button to send the email
    browser.find_element(By.ID,'Button_Send').click()
    time.sleep(3)

    navegador.close()

    #End#