Blocked Again After Sending 10,000 Verified Emails

Hello Support,

We verified our entire email list using your application before starting our email campaign. We had already verified 50,000 email addresses and confirmed that they were deliverable.

Following your advice, we started sending the emails in batches of 10,000 per day. However, we were blocked again after sending 10,000 emails.

We are only seeing soft bounces and no hard bounces, and all of the email addresses in the batch had already been verified as deliverable.

Could you please help us understand why we are being blocked again despite following your recommended sending limit and using a fully verified email list?

Thank you for your assistance.

Hi,

Thank you for sharing the details.

We checked the sending activity and found that the soft bounce rate exceeded the permitted threshold, which resulted in the sending being blocked.

We also found bounce responses such as: SMTP; 554 5.7.1 [CS01] Message rejected due to local policy.

This indicates that some recipient mail servers rejected the messages due to their local policies. Even though the addresses were previously verified as deliverable, email verification cannot guarantee successful delivery, as recipient-side policies and other delivery factors can change over time.

We are reopening your email sending access. However, please ensure that your email content is relevant and follows email-sending best practices, and monitor the bounce rate closely during future campaigns. If the bounce rate starts increasing, we recommend pausing the campaign and reviewing the affected recipients before continuing.

Please take care to avoid repeated high bounce rates, as this may result in sending restrictions again.