Companies often pause email marketing due to a change in strategy or technical failures, but resuming campaigns with an abrupt blast to the whole list is risky. Mass-sending emails after a long break risks domain blocking and loss of sender reputation.
Let's break down how to restart the channel without ending up in spam.
Why you can't just hit "Send"
About 20-25% of addresses become inactive every year due to job changes or abandoned mailboxes. If you send an email to such addresses, mail providers will register a high bounce rate, which hurts sender reputation.
Besides list aging, there are other risks too:
- Filter response. If a domain has been inactive for a long time and then sends thousands of emails, protective systems will block the campaign. Algorithms interpret this kind of activity as spammer behavior or the use of a purchased list.
- The human factor. Users forget they subscribed to you. If a user doesn't recognize the sender, they click "Spam". This damages the domain's reputation and reduces the deliverability of future emails.
Stage 1. Technical preparation
Before writing the email copy, you need to thoroughly clean up the list.
Validation. Remove invalid addresses and spam traps. Even a single hit on a spam trap can get the domain blacklisted (RBL).List cleaning guide
Signature check. Set up SPF, DKIM, and a DMARC policy. Without these records, mail services won't be able to confirm the sender's authenticity and will reject emails right at the server acceptance stage.What SPF, DKIM, and DMARC are
Segmentation. Start with the most active contacts — those who made purchases or subscribed shortly before the pause. This will ensure high open rates and help build a positive domain reputation.
Stage 2. Content and first-touch strategy
What matters to the user is current value, not excuses for a long absence. The first message should be informative and honest.
Subject line. Use neutral headlines without aggressive marketing or capital letters. Something like "Updates from [Company Name]" or "New content and experience for you" works well.
Content. Briefly explain the reason for resuming the campaign and confirm the value of your content with a link to an article or case study. Remind the user under what circumstances they subscribed to your updates.
Subscription management. Make the unsubscribe link visible. A user voluntarily leaving the list is safer for domain reputation than spam complaints.
Restrictions. Avoid direct sales pitches in the first email. The main task at this stage is to rebuild trust with mail providers and your audience.
Stage 3. Gradually increasing volume
Restoring work with the list requires caution. You can't send the entire volume of emails on the very first day.
Start with 500-1,000 messages a day to the most active segment. Increase the volume by 20-30% daily, provided technical metrics stay stable.
Metric monitoring:
Bounce rate shouldn't exceed 2-3%.Spam complaints have a critical threshold of 0.1%. If these values are exceeded, immediately stop the campaign to check the quality of the list and content.Why emails end up in spam in 2026
Stage 4. Working with inactive subscribers and final cleanup
Once the domain's reputation is confirmed on the active segment, you can move on to the rest of the list. Send a two-email chain with a specific offer: a promo code or access to exclusive content.
If a subscriber didn't open either of these emails, it makes sense to exclude them from regular campaigns. Keeping inactive addresses lowers overall open rates and can lead to technical blocks from mail providers down the line.
Resuming campaigns after a long break requires methodically rebuilding your reputation. This calls for cleaning the list beforehand, checking technical settings, and gradually ramping up send volume.
Use Letteros to safely get back to working with your list and make email marketing an effective part of your strategy.