![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(128, 66%, 22%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ESK%3C/text%3E%3C/svg%3E)
SQL Server Reporting Services
A SQL Server technology that supports the creation, management, and delivery of both traditional, paper-oriented reports and interactive, web-based reports.
3,065 questions
Hi @Scott Klein,
From the docu at https://sendgrid.com/docs/for-developers/sending-email/smtp-errors-and-troubleshooting/#550-unauthenticated-senders-not-allowed
If you’re getting an “Unauthenticated Senders Not Allowed” error, the problem usually lies in authenticating with our SMTP server. This error gets triggered when there was an attempt to hand over an email message through smtp.sendgrid.net before authenticating the connection with your SendGrid username and API key.
To fix this issue, you’ll want to make sure that you’ve configured your setup to connect to smtp.sendgrid.net using authentication, and that the credentials you’re using are your SendGrid username and a properly configured API key as the password. For more on API keys, see [API Keys](https://docs.sendgrid.com/ui/account-and-settings/api-keys/"API Keys").
If you’re using cPanel/Exim, you’ll want to make sure it’s configured to authenticate every time it connects to smtp.sendgrid.net.
Regards，
Zoe Hui
If the answer is helpful, please click "Accept Answer" and upvote it.