Why is my email getting throttled by Gmail and Microsoft despite high engagement and good reputation?

Despite high engagement and good sender reputation, email throttling by Gmail and Microsoft can be attributed to a multitude of factors, requiring a comprehensive approach to diagnosis and resolution. These factors range from sender reputation and email content issues to technical configurations and external influences. Specifically, sender reputation can be impacted by past sending practices, infrastructure issues, sudden volume spikes, or sending from newly created IPs without proper warm-up. Email content that contains suspicious keywords, poorly coded HTML, or imbalanced image-to-text ratios can trigger spam filters. Authentication failures, arising from missing or misconfigured SPF, DKIM, and DMARC records, raise suspicion with email providers. Poor list hygiene, resulting in high bounce rates or hitting spam traps, degrades deliverability. Moreover, failing to process feedback loops, issues with shared IPs, being listed on blocklists (even temporarily), non-compliance with email formatting standards (RFC 5322), and stringent DMARC policies can all contribute to throttling. Unseen backend triggers, such as infrastructure changes or algorithmic updates on the receiver's end, can also play a role. Effective monitoring using tools like Google Postmaster Tools and Microsoft SNDS, proactively managing sender reputation, consistently adhering to best practices in email content and list hygiene, implementing robust authentication, and actively resolving delivery issues through postmaster communication are crucial for mitigating throttling.

Despite high engagement and good reputation, email throttling by Gmail and Microsoft can occur due to various factors. These include sender reputation issues (past practices, infrastructure problems), email content (suspicious keywords, poor HTML), authentication problems (SPF, DKIM, DMARC), list hygiene (spam traps, bounce rates), feedback loop processing, shared IP issues, sudden volume spikes, blocklist status, and even infrastructure or algorithmic issues beyond the sender's immediate control. Monitoring tools like Google Postmaster Tools and Microsoft SNDS are crucial for identifying and addressing these problems.

Email throttling by Gmail and Microsoft, despite high engagement and a good reputation, can stem from underlying issues related to infrastructure, security, or non-transparent backend triggers. These issues are not always visible in standard email marketing metrics. Problems with email sending infrastructure, compromised servers, and unusual sending patterns can raise flags, leading to throttling. Algorithmic updates and temporary glitches can also result in delays.

Even with high engagement and good reputation, email throttling by Gmail and Microsoft can occur due to issues related to IP reputation, complaint rates, email formatting, and DMARC policy. Maintaining a good IP reputation is essential; sudden volume spikes or sending from new IPs without a warm-up can trigger throttling. Increased complaint rates, even small, can lead to throttling. Non-compliance with email formatting standards (RFC 5322) causes parsing issues. A DMARC policy set to 'quarantine' or 'reject' blocks failing authentication checks. Monitoring SNDS and reviewing DMARC reports are critical.