Best Practice for Sending Bulk Emails to Avoid Flags

Objective

This article will help SendGrid customers understand how to successfully send bulk emails without having their messages flagged by Fraud Operations for suspicious activity. If you are a new user planning to send high-volume, legitimate email traffic—such as more than 10,000 emails at once—this guide explains the steps you need to take to avoid deliverability issues, bounces, or opt-outs. You’ll learn how to properly warm up your IP addresses and maintain clean mailing lists to ensure your bulk email campaigns are not mistakenly flagged or blocked.

Product

Twilio SendGrid

Procedure 

To help ensure your sending goes smoothly and to minimize the risk of account flags or suspensions, here are some best practices and insights:

1. Mailing List Hygiene:
   • Please make sure your mailing lists are up-to-date and contain only recipients who have explicitly opted in.
   • Remove any invalid, bounced, or unsubscribed addresses before sending. This helps reduce bounce rates and the risk of being flagged for suspicious activity.
2. Sending Patterns:
   • If possible, gradually ramp up your sending volume (“warming up” your IPs) rather than sending all emails at once. Sudden, large spikes can sometimes trigger automated reviews, even for legitimate traffic.
   • If you anticipate a significant increase in sign-ups or engagement, providing details (expected volume, timeframe, and nature of the campaign) can help our teams better anticipate and monitor your traffic.
3. Content and Compliance:
   • Ensure your email content complies with anti-spam regulations (CAN-SPAM, GDPR, etc.) and includes clear unsubscribe options.
   • Avoid using language or formatting that could be interpreted as spammy/spoofing by filters.

Additional Information 

Sources: 

1. Mailing List Hygiene
   • Source: Email List Hygiene: 5 Tips to Keep Your Lists Clean | Twilio
   • Source: Email Deliverability Best Practices: How To Make It To The Inbox | Twilio
2. Sending Patterns & IP Warming
   • Source: IP Warm-Up for Email Deliverability | Twilio
   • Source: Best Practices for Automated IP Warmup – SendGrid
3. Content and Compliance
   • Source: Best Practices for Email Deliverability – SendGrid
   • Source: Avoiding Spam Blocking Best Practices – SendGrid
4. General Deliverability Guidance
   • Source: Email Deliverability Best Practices: How To Make It To The Inbox | TwilioMail Settings Guide within a SendGrid Account