title: smtplib.SMTPRecipientsRefused: How to fix smtplib error in Python?
body: <p>Fairly frustrating - I put this in IDLE / terminal:</p>
  
  <pre><code>import smtplib
  server = smtplib.SMTP('smtp.mail.com', 587)
  server.starttls()
  server.login("emailaddress@mail.com", 'password')
  msg = "duck"
  server.sendmail("emailaddress@mail.com", "emailaddress@mail.com", msg)
  </code></pre>
  
  <p>Here's the annoying part - this worked twice, but then when I tried it a third time and thereafter, it just stopped working, getting the following error message:</p>
  
  <blockquote>
    <p>File "C:\Users\duck\AppData\Local\Programs\Python\Python36-32\lib\smtplib.py", line 880, in sendmail
        raise SMTPRecipientsRefused(senderrs)
    smtplib.SMTPRecipientsRefused: {'emailaddress@mail.com': (550, b'Requested action not taken: mailbox unavailable\nFailure sending mail. Try again later')}</p>
  </blockquote>
  
  <p>I've tried emailing it to the same address I'm sending it from, and a different address - no cigar.</p>
  
  <p>The fact that it was working earlier - but suddenly stopped, does that mean that mail.com limits emails from being sent via smtp? How would I know what if this is a mail.com issue or something I can fix on my end?</p>
  
  <p>I've tried the 'ehlo' command before the starttls() - and it didn't work for me. This was suggested in some other questions about error 550.</p>