Deliverability after a long pause

PROBLEM 01 · DOMAIN REPUTATION

Gmail resets domain reputation after around 30 days of inactivity. So if you haven't sent anything in a while, your reputation data is just gone. If you go into Google Postmaster Tools right now you will see no data for the last 90 days. That is Gmail telling you it doesn't know who you are anymore.

Same logic applies to Microsoft and Yahoo. You are basically a new sender again.

Most people don't realise this until after they send. They hit their list, open rates tank, spam complaints come in, and they assume the list is dead. Sometimes it is. But a lot of the time the problem is that they skipped the warmup and went straight to volume.

Before you send anything, check your authentication. SPF, DKIM, and DMARC can drift while you're not sending. Hosting changes, new tools added to the stack, someone touched the domain settings. Run your domain through MXToolbox and verify everything is still intact. A broken DKIM record on your first comeback send is an easy way to get filtered immediately.

Set up Google Postmaster Tools if you haven't already. You need visibility into what Google thinks of your domain before you start sending again, not after.

PROBLEM 02 · BAD RE-ENGAGEMENT

There is no one-size answer here. How you come back depends on how long you've been gone.

1-3 months gone: your reputation has taken a hit but it's not gone completely. Don't blast your full list. Start with your most engaged segment and ramp slowly over 2-4 weeks. No big volume spikes. ISPs are watching you like a new sender and big spikes trigger filters.

3-9 months gone: a big chunk of your engaged subscribers have moved on. Before you send, suppress everyone who never opened anything. They are dead weight and sending to them drags your engagement metrics down, which signals to ISPs that nobody wants your emails. Work from your most engaged contacts outward and accept that your sendable list is smaller than you think.

9 months or more: this is where it gets different. Trying to reengage a cold list that old is genuinely hard. My honest advice here is to not start with your old list at all. Start by getting fresh subscribers first. Run ads, activate a lead magnet, do whatever gets you new opted-in contacts. Fresh subscribers give you real engagement signal to rebuild your domain reputation on. Once you have some momentum established, then go back to your old list and remind them why they signed up. You will see complaints and unsubscribes. That is expected after that long. But some of them will remember you and stay. The ones who do are worth having.

PROBLEM 03 · WHAT NEXT?

Treat this exactly like a domain warmup because that is what it is.

Start small. Send to your most engaged segment only. Don't spike volume. Increase sends gradually over 2-4 weeks and watch your Postmaster Tools dashboard as you go. You want to see domain reputation move from no data to medium to high. If it drops or you see spam rate increases in the dashboard, slow down before your next send.

On the content side, don't over-explain the gap. One sentence acknowledging you've been away is enough. Your subscribers don't need a full explanation. They need a reason to keep reading. Give them something useful straight away and move on.

Watch your complaint rate closely. It should stay under 0.1%. If it goes above that, suppress more before you send again. A 5-8% open rate on a cold comeback is normal. Under 3% means you have more suppression work to do before you increase volume.

Before You Go: Here's How I Can Help

— Pavel