Email Marketing · 11 November 2025 · 1 min read

Black Friday and 11.11 Email Checklist: Get Into the Inbox When It Matters Most

Gmail, Yahoo and Outlook now all require authentication for bulk senders. Here's a sale-season checklist to protect inbox placement during your highest-volume weeks of the year.

In short:

All three major inbox providers (Gmail, Yahoo, Outlook) now require SPF, DKIM and DMARC for bulk senders.
Sending far more email than usual to unengaged contacts is the fastest way to land in spam during sale season.
Segment by engagement, increase volume gradually and keep spam complaints under 0.3%.

Sale season is when email earns the most, and when it’s most likely to go wrong. In one skincare account we manage, email ROI rose from about 2.0x in September to 2.7x in October 2025 after we rebuilt the flows and cleaned the list, before the sale season even started. The difference wasn’t sending more. It was sending better.

The checklist

Authentication

SPF, DKIM and DMARC pass for your sending domain (Gmail and Yahoo since 2024, Outlook since May 2025).
One-click unsubscribe works.

List and segments

Suppress contacts with no opens or clicks in 6+ months for big campaigns.
Create segments: engaged 30 days, engaged 90 days, past buyers, VIPs.
Send the most emails to the most engaged. Send the least engaged one or two emails at most.

Volume

Increase sending gradually in the weeks before the sale. Don’t go from 2 emails a month to 2 a day.
Spread big sends over an hour or two instead of one blast.

Content

Clear subject lines. Avoid ALL CAPS and stacks of emojis and exclamation marks.
Balance images and text. Make sure the email still makes sense with images off.
Delivery deadlines and COD details clearly stated.

Monitoring

Check Google Postmaster Tools for spam rate and domain reputation every day of the sale.
Pause sending to a segment if complaints or bounces spike.

Flows still do the heavy lifting

Campaigns get the attention, but flows quietly do the selling: abandoned cart, browse abandonment, welcome and post-purchase. Make sure they’re on, tested and updated with sale messaging before traffic peaks.