January is the easiest month to fix your email program. Q4 is over, volume is low, stakeholders are patient, and the year-long calendar is still a blank page. By February, the product launches start, by April the growth team has volume plans, and by July everyone is firefighting. If you're the marketer who owns email, this checklist is what you close between the second week of January and the end of the month. Eleven items, three hours each, done.
Copy the eleven items into a Notion or Linear doc. Assign each a target date. Mark them done as you go. At the end of January the doc is your deliverability audit report for the year.
1. Establish a fresh placement baseline
Before you change anything, know where you stand. Run a full inbox placement test across Gmail, Outlook, Yahoo, Mail.ru, Yandex, ProtonMail, and any provider your audience uses. Save the report. This is your January baseline. Every improvement this year is measured against it.
2. Re-verify authentication
Someone on your engineering team changed DNS in 2026 and forgot to tell you. Someone added a vendor to SPF that isn't there anymore. DKIM rotation is one selector behind. Re-run SPF, DKIM, and DMARC checks for all sending domains (marketing, transactional, sales). Fix anything failing before February. Everything downstream of authentication is fantasy if authentication is broken.
3. Do the annual suppression
Every subscriber who hasn't opened or clicked in 12 months is dragging your program down. I know you paid for them. Remove them anyway, or move them to a separate re-engagement track. List quality matters more to placement than sender reputation in 2026 — Gmail and Yahoo now punish senders whose engaged segment is under a third of total list.
4. Rebuild segments
Last year's segments are stale. The "engaged last 90 days" segment is half the size it was six months ago. The "purchased in last 180 days" segment has holiday noise in it. Rebuild the three segments you actually send to weekly. Write down the criteria so Q3-you doesn't have to reverse-engineer them.
5. Lock the volume calendar
Look at the whole year. Mark the expected high-volume periods (BFCM, product launches, regulatory deadlines). Mark the low-volume periods. Mark when you will ramp (3–4 weeks before volume surges) and when you will rest (2–3 weeks after). ISPs punish volume shocks. A calendar locked in January prevents February's panic send.
6. Review consent and unsubscribe
New regulations came into force in 2025 and 2026 across several jurisdictions. Check that your unsubscribe link works in one click (Yahoo and Gmail sender rules), your List-Unsubscribe header is present, your consent records are exportable, and your retention policy for inactive users aligns with your ToS. This is the item most likely to bite you in a CASL, GDPR or 152-FZ complaint.
7. Retire the content patterns that tanked
Pull 2026's worst-performing campaigns by inbox placement (not open rate — placement). What do they have in common? Subject line style, time of day, day of week, from-name, template? Make a list of three patterns you commit to not using in 2027. Write it on the team wall.
8. Audit transactional separately
Marketing and transactional fail for different reasons and need separate attention. Run a second placement test for each transactional sender (password reset, receipts, order confirmations). These are usually on different domains or subdomains, with different DNS, different ESPs, and different filter treatment.
Run separate tests from each of your sending domains:no-reply@app.yours.com,hello@yours.com, billing@yours.com. The free test shows placement per sender so you can see which domain needs love.
9. Set up alerting
You shouldn't find out about a deliverability problem by seeing an unhappy dashboard screenshot in Slack two weeks late. Set thresholds and alerts: spam rate over 0.3% daily, placement dropping under 70% week-over-week, bounce rate over 2%, new blocklist listing. Pipe them to the channel the email owner actually reads. Most ESPs have this built-in; use it.
10. Review your vendor stack
Every vendor with "email" in their name that sends on behalf of your domain needs to be (a) in your SPF, (b) DKIM-signing correctly, (c) reviewed for reputation, and (d) still being used. The common failure: a vendor you stopped using six months ago is still in SPF, still signing with an expired DKIM key. Clean the list. Remove what isn't used.
11. Put the next review on the calendar
Schedule the Q2 review in April and the Q3 review in July before you finish this document. If you don't, you won't do them. The quarterly review is the difference between a program that drifts into trouble and one that catches problems early. See the quarterly review template for the meeting format.
Time budget
Roughly 30 hours for the whole checklist if you've never done it, 10 hours if you have a baseline from last year. If you only have time for three items, do these: placement baseline (1), authentication (2), and alerting (9). They catch 80% of the problems you'd otherwise discover mid-year with a fire.