Gmail handles over 1.8 billion active accounts and processes more email than any other provider on the planet. When Google changes how it scores, filters, and routes email, those changes redefine deliverability standards for the entire industry. Every other ISP watches Gmail's policies and adjusts.
This Gmail deliverability guide reflects what Google has implemented as of 2025 and what remains enforced into 2026 — the bulk sender requirements, the authentication mandates, the complaint thresholds, and the inbox placement signals that determine whether your email reaches the inbox or disappears.
What Changed: Gmail's 2024 Bulk Sender Requirements
In February 2024, Google began enforcing a set of requirements for senders who send more than 5,000 emails per day to Gmail addresses. Non-compliance results in the email being marked as spam or rejected outright. These requirements remain in force and are now the baseline standard:
SPF or DKIM authentication is mandatory. Both are strongly recommended; SPF alone is no longer sufficient for most bulk senders.
