Below are several steps to troubleshoot your issues with sending emails to multiple recipients:

1. Check your connection: Be sure your internet connection is working properly.
2. Check your email app’s settings: Make sure your email client is properly configured for the email address(es) you’re sending from. You can find more help in the app settings.
3. Check the email provider’s settings: If you’re using an email provider, such as Google or Microsoft, you can verify that the correct settings are configured.
4. Check your email list: If you’re sending to many recipients at once, most email services require that you send to no more than 10. If you’re sending larger mailings, you may need to consider switching to an email marketing service.
5. Check the email recipient’s spam folder: If the email address is not accepting your emails, it could be possible that it is going to the recipient’s spam folder instead of their inbox.