Why Are My Inboxes Still Warming?
Inbox warmup is the process of gradually building a sending reputation with Gmail, Outlook, and other mailbox providers before your campaign goes live at full volume. It is not optional; skipping warmup or rushing it is one of the fastest ways to get a domain flagged as spam.
Here is a plain explanation of why it takes time, what is happening behind the scenes, and what to do if something seems off.
Why Warmup Is Necessary
When a new domain and inbox are created, they have zero history with any mailbox provider. A brand new inbox that suddenly starts sending 50+ cold emails a day looks identical to a spam operation, because that is exactly what spam operations do. They register domains in bulk, skip warmup, blast thousands of emails, and move on before getting flagged.
Mailbox providers know this pattern and use it to filter incoming mail. A new inbox sending at volume without any reputation history will get throttled, filtered to spam, or blocked outright.
Warmup solves this by building a track record. We start low (5-10 emails per day per inbox), generate real positive engagement (replies, opens, moving emails out of spam), and increase volume gradually over several weeks. By the time your campaign goes live, each inbox has a sending reputation that says: this is a legitimate sender, not a new spam account.
The Standard Warmup Timeline
Most inboxes reach the threshold for campaign launch, typically 85%+ average reputation, in 22 to 28 days. A small number take up to 35 days.
The timeline depends on several factors:
Domain age. Freshly registered domains warm more slowly than domains with some age behind them. A domain registered yesterday has no history at all, while a domain registered six months ago, even if unused for sending, has a small amount of passive history that helps. Piqely registers fresh domains for each PIQ Pro client, so the 22-28 day timeline applies in most cases.
Mailbox provider mix in the warmup pool. Gmail-to-Gmail emails warm Gmail reputation, and Outlook-to-Outlook emails warm Outlook reputation. We use a mixed warmup pool that covers the major providers, so your inboxes build reputation where it matters for your target audience.
Reply rates during warmup. Warmup works by generating positive engagement signals through emails that get opened, replied to, and not marked as spam. If the warmup system is generating weak engagement signals during the process, it slows down. This is rare but can happen.
Sending domain history. If a domain has prior negative history such as previous spam activity, blacklist entries, or a poor reputation from a previous owner, warmup is harder and takes longer. Piqely uses fresh domains specifically to avoid inheriting someone else's problems.
Reading Your Warmup Status
In your portal, go to the Campaigns page. If your campaign is in pre-launch warmup status, you will see a warmup card showing:
- Avg Reputation: the current average inbox reputation across all 12 inboxes. You want this at 85% or above before launch. It is normal for this to be in the 40-60% range in the first week and a half.
- Progress bar: a visual indicator of overall readiness. Do not treat this as a precise countdown, as it is a directional signal.
- Est. Go-Live: an estimate based on current trajectory. This updates as warmup progresses.
- A specific mailbox provider started filtering warmup emails to spam (we monitor for this and rotate inboxes if needed)
- A sending IP was added to a blocklist (we check this daily and rotate off affected IPs)
- Technical configuration issue with SPF, DKIM, or DMARC records (we verify these at setup but occasionally something changes at the DNS level)
- Review and finalize your ICP parameters with your CSM
- Approve the copy for your launch sequences
- Set up any integrations you want active at launch (Google Calendar, CRM webhooks)
- Brief your sales team on what to expect when meetings start coming in
Individual inboxes warm at slightly different rates. Some will hit 85% before others. We wait for the full set of 12 inboxes to be ready before launching, as launching with mixed-reputation inboxes creates inconsistent results.
What "Stalled" Actually Looks Like
Warmup rarely stops completely, but it can slow down. A slow period usually looks like reputation advancing 1-2% per day instead of 3-5% per day. This is normal and usually corrects itself within a few days.
A genuinely stalled warmup, where reputation has not moved in 5+ days, is uncommon. When it happens, the causes are usually:
If your Est. Go-Live date has come and gone without a campaign launch notification, reach out to your CSM. That is the signal to investigate rather than just wait.
Standard vs. PIQ Pro Warmup
If you are on the Standard plan, your campaign launches on Day 1 because you are sending from Piqely's pre-warmed shared infrastructure. There is no warmup period for Standard clients, as the inboxes are already ready.
If you are on PIQ Pro, your campaign uses 12 dedicated inboxes on branded domains registered specifically for you. These start fresh and go through the full warmup cycle, typically 22 to 28 days, before your campaign goes live. The tradeoff is worth it: dedicated inboxes with isolated reputation generate significantly higher reply rates than shared infrastructure.
If you are waiting on warmup right now, you are on PIQ Pro. The wait is part of what makes the performance better once you launch.
What You Can Do During Warmup
You do not need to do anything during warmup, as it runs automatically. However, this is a good time to:
Questions
If you have questions about your warmup timeline or status, contact your CSM directly through the chat widget in the portal or email support@piqely.com.