Email warmup is the practice of building a mailbox's sending reputation by exchanging realistic emails with other trusted mailboxes. This teaches Google and Microsoft that your mailbox behaves like a real person — not a bulk sender.
The problem with one-time warmup
Most outreach tools offer a warmup phase — typically 2 to 6 weeks — and then tell you to switch it off once you're ready to send campaigns. This creates an immediate problem.
A mailbox that has been warmed up for 3 weeks and then suddenly switches from 20 warmup emails per day to 50 cold campaign emails per day looks very different to Google. The pattern breaks. The sending behaviour changes. And over time — sometimes within weeks — the domain score starts to decline.
❌ One-time warmup (other tools) | ✓ Continuous warmup (GetReplies) |
Warm up for 2–6 weeks | Connect mailbox |
Switch warmup off | Warmup runs continuously alongside campaigns |
Start sending campaign volume | System balances warmup and campaign sends daily |
Domain score gradually declines | Domain score is maintained and grows over time |
Emails start landing in promotions or spam | Emails consistently land in primary |
Open and reply rates drop | Reply rates stay healthy |
Have to restart warmup from scratch | Nothing to restart — warmup never stopped |
How continuous warmup works in GetReplies
When you connect a mailbox, GetReplies immediately begins warmup. This warmup never stops — even when you are actively running campaigns. The system runs both simultaneously, every day.
Here is what happens behind the scenes on a typical day for a connected mailbox:
| ⚙ Daily mailbox activity — what GetReplies does each day |
Warmup sends | System sends a set of realistic emails to trusted warmup network mailboxes |
Warmup receives | Warmup emails arrive in your inbox and are automatically marked as not spam |
Warmup replies | Some warmup emails receive replies, creating normal two-way engagement |
Campaign sends | Campaign emails go out to your prospects within your daily limit |
What the warmup limit controls
In your mailbox settings you will see two separate limits:
Daily warmup limit. The number of warmup emails the system will send and receive per day. This is managed automatically — you do not need to change it.
Daily campaign limit. The maximum number of campaign emails your mailbox will send per day. This is what you set.
The two limits run independently. The warmup limit is always on in the background. Your campaign limit is what you control.
How the coin-toss sending mechanism works
GetReplies doesn't send all your campaign emails in a burst at the start of the day. Every 3 minutes, the system makes a probabilistic decision: send an email now, or wait?
This creates a natural, randomised sending pattern across your active hours — which looks exactly like a real person sending emails throughout the day, rather than a bulk sender firing off 50 emails in one go.
At 50% probability over an 8-hour window, you get roughly 80 send opportunities — which maps to your campaign limit of around 20–50 emails depending on your settings.
Should I turn warmup off for older mailboxes?
No — and this is one of the most common mistakes teams make when switching to GetReplies from other tools. Even if your mailbox is months or years old, continuous warmup still provides value:
It counteracts the signal from campaign bounces, which will always occur to some degree
It maintains the positive engagement pattern that keeps your domain score healthy
Email service providers update their scoring continuously — a dormant mailbox can lose reputation even without you doing anything wrong
For older mailboxes, simply leave warmup on and skip the ramp-up feature (which is only needed for new mailboxes). Set your campaign limit manually to whatever you're comfortable with — 30 to 50 per day is sensible for a well-established mailbox.