Why are my customer.io emails not delivering when using sendgrid?
Summary
What email marketers say8Marketer opinions
Marketer from Email Geeks (Deliverability Services Manager at Customer.io) offers direct support to investigate the Sendgrid/Customer.io integration issue, recommending the user contact the support team.
Email marketer from Mailgun recommends verifying domain authentication settings (SPF, DKIM, DMARC) and monitoring the sender reputation. It also recommends checking for any blocks or restrictions.
Email marketer from StackOverflow notes that gmail has strict authentication rules. The configuration settings might need to be updated to adhere to their rules and allow for the emails to be delivered.
Email marketer from EmailGeeks Forum shares that a common cause is incorrect configuration of the Customer.io integration with SendGrid. They advise double-checking the API keys, webhooks, and event tracking settings to ensure they are properly set up.
Email marketer from Reddit suggests checking SendGrid's activity feed and suppression list for bounces and blocks. Also recommends verifying that the SendGrid account is properly authenticated with SPF, DKIM, and DMARC records.
Marketer from Email Geeks suggests using SMTP logs from SendGrid to investigate delivery issues with Customer.io and advises checking the "suppression" bounce/blocks to understand why so few emails are being delivered.
Email marketer from EmailOnAcid says that your IP address could be blacklisted. This can happen if there's a history of spam or poor sending practices associated with the IP.
Email marketer from Quora suggests that rate limiting can cause issues with Sendgrid. Check the account limits to ensure that you are within the quota
What the experts say3Expert opinions
Expert from Spam Resource explains that problems can be related to your sending infrastructure. Shared IP addresses may have poor reputations, and dedicated IP addresses need to be properly warmed up. Also ensure that reverse DNS is set up correctly.
Expert from Email Geeks asks if the bounce reasons are accessible and what they indicate, to help troubleshoot the email delivery problem.
Expert from Word to the Wise (Laura Atkins) explains that poor list hygiene practices and acquiring email lists can significantly harm your sender reputation and lead to deliverability problems. Focus on obtaining opt-in contacts and removing inactive subscribers.
What the documentation says4Technical articles
Documentation from Customer.io explains that the IP address should be warm before any emails are sent out. Otherwise the deliverability score can be affected and emails sent to spam.
Documentation from RFC explains that if the SMTP server cannot deliver the message for some reason, it MUST construct and mail a notification message. It is important to understand these bounce codes to diagnose issues.
Documentation from SendGrid explains that common reasons for delivery issues include incorrect DNS settings, poor sender reputation, high bounce rates, and spam complaints. It recommends monitoring bounce codes and feedback loops to identify and resolve problems.
Documentation from SparkPost explains that content within emails, such as URLs, keywords, or attachments can be flagged and seen as spam by spam filters.