Why email goes to Gmail spam
Gmail considers a blend of technical trust, user engagement and message-level signals. Authentication is required, but it is not the finish line.
Authentication first
Make sure SPF, DKIM and DMARC all pass where expected. Gmail is less forgiving when authentication is partial, inconsistent or misaligned.
Reputation and volume
Sudden spikes, poor list quality and repeated complaints can quickly affect inbox placement. New domains and IPs need consistent behaviour, not random bursts.
Content and links
Suspicious links, mismatched branding, overloaded images, deceptive subjects or mail that feels unexpected for the audience can all worsen placement.
What to do next
Review Gmail-specific spam placement patterns over time, not just one campaign.
Reduce sends to disengaged addresses.
Use a clear unsubscribe path.
Keep domain and IP reputation stable.