550 mail rejected

A common issue!

When you see "550 mail rejected" in your email client or server logs, it usually means that the email you're trying to send has been rejected by the recipient's email server. Here are some common reasons why this might happen:

  1. Invalid recipient email address: The email address you're trying to send to is invalid, non-existent, or not properly formatted.
  2. Domain or server issues: The recipient's email server is down, experiencing technical difficulties, or has a configuration issue that's preventing emails from being delivered.
  3. Spam filters: The recipient's email server has flagged your email as spam or junk mail, and is rejecting it.
  4. Blacklisting: Your IP address or email server has been blacklisted, which means that the recipient's email server is blocking your emails.
  5. Authentication issues: Your email server is having trouble authenticating with the recipient's email server, which is preventing the email from being delivered.
  6. Content restrictions: The recipient's email server has restrictions on the types of content that can be sent, and your email is violating one of these restrictions.

To troubleshoot the issue, you can try the following:

  1. Check the recipient's email address: Make sure the email address is valid and properly formatted.
  2. Verify the recipient's email server: Check if the recipient's email server is down or experiencing issues.
  3. Check your email client or server settings: Ensure that your email client or server is properly configured and authenticated.
  4. Check your email content: Make sure your email content doesn't violate any content restrictions or spam filters.
  5. Try sending a test email: Send a test email to the recipient to see if the issue is specific to a particular email or if it's a general issue.
  6. Contact your email provider or IT department: If you're still having trouble, contact your email provider or IT department for assistance.

I hope this helps you troubleshoot the issue!