Test deliverability issues

Run a deliverability test for the upcoming weekly newsletter to see if it will land in inboxes. Send test messages to Gmail, Outlook, and a mobile client, check spam-folder placement and header authentication results, and produce a one-page list of immediate fixes (subject lines, links, send cadence) before the Thursday send window.

Before I send the list to the creative lead, surface the three deliverability risks they can act on: problematic subject lines, spammy link domains, and image-to-text ratio. Highlight the one change that will give the biggest inbox-win and mark any items that require legal approval.

I ran test sends and Gmail delivered to Promotions while Outlook put the same message in Junk. I'm the marketer and I can't interpret whether subject, authentication, or content is to blame. What is the most likely cause of divergent placement and what exact tweak should I try first to improve overall inboxing?

We keep doing test sends yet repeat the same issues week after week. Are we failing to track the right metrics, not assigning ownership for fixes, or altering too many variables at once? Recommend one habitual metric to record and one small experiment to run that will give reliable learning about audience inboxing.