It seems that the error "Access denied, bad outbound sender AS(42004)" is causing your sent emails to bounce back. This error typically indicates that the email server has identified your outbound emails as potentially harmful or spammy, and therefore, it is blocking them.
Here are a few steps you can take to resolve this issue
Check Email Content: Ensure that your emails do not contain any content that might be flagged as spam. Avoid using excessive links, images, or suspicious phrases.
Verify Email Settings: Make sure your email settings are correctly configured. This includes checking your SMTP server settings and ensuring that your email client is properly authenticated.
Review Email Sending Limits: Some email providers have limits on the number of emails you can send in a certain period. Ensure you are not exceeding these limits.
Check for Blacklisting: Verify if your email address or domain has been blacklisted. You can use online tools to check this and request removal if necessary.
If you need further assistance, please let me know!
