KoltrixRestarting a quiet sending domain after months of silence
A domain that stopped mailing for months does not keep its old reputation. How to audit, clean the list, restart at low volume and ramp up without damage.
On this page(9 sections)
- What happens during a long pause
- Step one: audit the setup before any mail goes out
- Step two: decide who should still get mail
- Step three: restart small, with your best audience
- Step four: ramp up gradually, and read the numbers
- Step five: handle the less active group carefully
- If something goes wrong
- Avoiding the next long silence
- Key takeaways
A company sent a newsletter every month for two years, then paused during a product rebuild. Eight months later the new site is ready, and someone asks the obvious question: can we just send to the old list again? The domain has a good history, after all.
Unfortunately a good history does not work like savings in a bank. Mailbox providers care mostly about what a sender has done recently, and a domain that went quiet has, in effect, lost its recent record. Meanwhile the list has aged, and some addresses have gone bad in ways that hurt. Treat the restart more like a careful launch than like pressing a button that was left unpressed.
This guide covers what changes during a long silence, what to check first, and a restart plan that protects the domain you have.
What happens during a long pause
Three things drift while you are not looking.
Reputation fades. Providers do not publish exact rules, but the principle is well known: reputation is built from recent volume, complaints, bounces and engagement. After months with no mail, there is little recent evidence to lean on, and a sudden burst looks unfamiliar. A sender that looks new gets the cautious treatment given to new senders. How to warm up a new domain explains why.
Your list decays. People change jobs, abandon accounts and close mailboxes. Providers turn some abandoned addresses into spam traps, which exist only to catch senders who mail without good list hygiene, and they recycle others. A list that was clean eight months ago may contain a meaningful number of addresses that now bounce or catch you out. See spam traps explained for the difference between types.
Your setup drifts. DNS records get changed during a website or hosting migration. A DKIM key may have been rotated or removed. A marketing tool may have been cancelled, but its record is still in SPF. The old email service may no longer be authorized. Nothing breaks visibly until you send.
Step one: audit the setup before any mail goes out
Spend an hour here, because everything else depends on it.
- Check SPF. There should be one SPF record, under the ten-lookup limit, that includes the services you will actually use. Remove services you no longer use. The SPF 10-lookup limit is the usual trap.
- Check DKIM. Confirm that the selector your sending service uses exists in DNS and verifies. Send a test to an address you control and read the headers for
dkim=pass. - Check DMARC. Make sure a record exists and that reports reach a mailbox someone reads. Confirm alignment: the domain in the visible From address should match the domain that passes SPF or DKIM. A 30-minute email authentication audit walks through it in order.
- Check the reverse DNS and sending IP, if you use a dedicated one, and check that your domain and IP are not on a public blocklist. Blocklist delisting playbook is useful if something shows up.
- Review your sender identity. The From name, reply-to address and the postal address in the footer should be current. A mailbox that receives replies must exist and be monitored.
- Confirm the unsubscribe flow works. Click your own unsubscribe link and confirm that it takes effect.
Do not skip a step because the setup "has not changed". The pause is exactly when things change without anyone noticing.
Step two: decide who should still get mail
The most important decision is the list. Mailing the whole old list to save time is how restarts go wrong.
Start from permission and recency. Rank your contacts by the last time they showed any sign of life: an open, a click, a reply, a purchase, a login. Anyone who has been active within the last six months is a reasonable first group. List hygiene and removing inactive subscribers covers the details.
Remove what you know is bad.
- Addresses that bounced before the pause. Respect your suppression list, and never remove an entry from it to get the numbers up.
- People who unsubscribed or complained.
- Role addresses and obvious junk.
- Addresses collected in ways that did not clearly ask for consent.
Verify the oldest part of the list. For contacts with no activity in more than a year, consider a verification service to catch dead mailboxes, and treat the results as a filter and not a guarantee. A better step for important contacts is a re-permission message sent in small batches (see below).
Be honest about consent. If people signed up long ago and might not remember you, say who you are and why they are hearing from you. The shorter the memory, the higher the complaint risk.
Step three: restart small, with your best audience
Plan the first messages as a test of your reputation, not a campaign.
- Send first to the most engaged group, such as people who opened or clicked in the last 90 days. They are the most likely to open, which helps rebuild a positive record.
- Start at low volume. A few hundred to a couple of thousand messages a day is a sensible starting point for most lists, depending on how much you normally send. Your own history and your provider's guidance set the exact figure.
- Send something people want. A useful update or announcement beats a heavy promotion. Keep the first messages simple and light on images and links.
- Make the first message a hello. "We have been quiet while we rebuilt X. Here is what is new" explains the gap and invites a reply. Replies are a strong positive signal.
- Make unsubscribing easy. A visible link and the one-click header protect you from complaints. See one-click unsubscribe.
Step four: ramp up gradually, and read the numbers
Increase volume only when the last step went well. A common pattern is to roughly double the daily volume every few days while the numbers stay healthy, and to bring in the less active groups last. An IP warm-up schedule offers a table you can adapt, although it was written with a new IP in mind.
At each step, check:
| Signal | Healthy | Slow down or stop if |
|---|---|---|
| Hard bounces | Well under 1 percent | Rising, or above 2 percent |
| Spam complaints | Well under 0.1 percent | Near or above 0.3 percent |
| Deferrals (4xx) | Rare | Many at one provider |
| Placement | Inbox for seed tests | Spam folder at a major provider |
| Engagement | Stable or rising | Falling with each step |
These are rules of thumb, not promises from providers. Spam complaint rate thresholds explains the numbers that matter most for Gmail and Yahoo.
Set up monitoring before you begin. Google Postmaster Tools shows domain reputation and spam rate for Gmail recipients, and your sending provider's dashboard shows bounces and deferrals for the rest.
Step five: handle the less active group carefully
For contacts who have been silent a long time, use a re-permission series.
- Send a short, honest message to a small slice: who you are, what they signed up for, a clear button to stay and an obvious way out.
- Give them a week or two to respond.
- Keep those who click or reply. Keep mailing those who open, but watch them closely.
- Stop mailing anyone who does not respond. You can try one more attempt later, but the second silence is an answer.
It feels wasteful to leave part of the list unmailed. It is cheaper than a damaged domain, and a smaller list that engages often outperforms a larger one that does not.
If something goes wrong
- Bounces spike. Pause the send, find which group they came from and suppress those addresses. Do not resume until you know why.
- A major provider defers or blocks. Reduce volume to that provider, check your authentication results and read the provider's guidance. Move slowly back up.
- Complaints rise. Stop mailing the group, review what you sent and how they were added, and fix the cause before sending more.
- You hit a spam trap. Treat it as a list quality problem. Narrow the list to recent, confirmed contacts and review where addresses come from.
Keep a log of volumes, results and decisions. When the restart is complete, you will have a template for the next one.
Avoiding the next long silence
If sending is going to be rare, such as an annual report or an event, consider keeping a small, steady flow of mail, such as transactional messages or a short monthly note to the engaged group, so the domain keeps a recent record. Keep marketing and transactional mail separated, as described in the case for a sending subdomain, so that one cannot hurt the other.
Key takeaways
- A long silence erodes your recent record, and the list and your DNS setup both drift in the meantime.
- Audit SPF, DKIM, DMARC, blocklists and sender details before sending anything.
- Rank contacts by recent activity, remove known-bad addresses and never mail the whole old list at once.
- Restart with your most engaged group at low volume, then ramp up while watching bounces, complaints and placement.
- Use a short re-permission series for the long-silent group, and stop mailing people who do not answer.
Start with Koltrix
Your domain, one inbox, and an API that sends.
A team inbox where AI sorts and drafts (nothing is sent without your click), plus the transactional API and SMTP relay your product sends with. 7 days free, no card.
