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Why is warm-up not running?

In short

Why is my Reply mailbox not warming up?

Enabling warm-up on a mailbox and connecting it to the warm-up service are two separate steps, and the second is the one people miss. Open the mailbox's own warm-up tab and confirm it shows as connected, not just switched on.

Quick fix

Open Settings → Email Accounts, select the mailbox, and open its Warm-up tab. This is the reliable route; the warm-up section elsewhere in the menu is not always where people expect.
Check whether the mailbox is connected, not just whether the toggle is on.
If it is not connected, use Connect and save, then wait for the mailbox to appear as active.
Confirm the mailbox itself is connected and healthy; warm-up cannot run through a mailbox that cannot send.
Check again the next day. Warm-up activity is low by design at the start and is easily missed.

Didn't work? Contact Reply support; the team can check your account directly.

Symptom

Warm-up appears enabled but no warm-up mail is being sent or received, or a mailbox added recently never started warming while others did.

Most likely causes

Cause	How to recognize it
The mailbox was never connected to the warm-up service	The toggle is on and the mailbox's warm-up tab does not show it as connected. By far the most common
The mailbox itself is disconnected	Warm-up depends on the mailbox being able to send and receive – see Why was a mailbox disconnected?
Warm-up seats are used up	A new mailbox cannot be added to warm-up while the allowance is full
It is running, quietly	Early warm-up volume is deliberately small. Nothing visible does not mean nothing happening
The domain is failing authentication	Warm-up mail from an unauthenticated domain bounces – see Why does my domain fail its DNS check?
The mailbox was suspended	The provider restricted it, so nothing sends, warm-up included

Diagnostic checklist

Check connected, not enabled. These are different states and the difference is the answer most of the time.
Check the mailbox's own health first. Warm-up rides on the mailbox; a disconnected mailbox warms nothing.
Check the seat allowance if the mailbox is new and others are warming normally.
Check the domain's authentication. Warm-up on a domain that fails authentication does harm rather than good.
Give it a day before concluding anything. Warm-up starts small on purpose.

Resolution

It was never connected

Open the mailbox's Warm-up tab, use Connect, choose a profile and save. Warm-up begins on the next cycle rather than immediately.

The mailbox is disconnected

Fix the mailbox first. Warm-up resumes on its own once the mailbox can send and receive again.

Warm-up seats are full

Either free a seat by removing warm-up from a mailbox you no longer send from, or add capacity. A mailbox cannot warm without a seat.

Authentication is failing

Fix SPF, DKIM and DMARC before warming. Warming an unauthenticated domain teaches receivers the wrong thing about it.

It is running and you cannot see it

Check again over a few days rather than a few hours. Volume climbs gradually; that gradualness is the entire point.

Verification

Open the mailbox's warm-up tab and confirm it reports as connected and active. Then check again after two or three days and confirm volume is climbing rather than flat.

Prevention

Connect warm-up as part of adding a mailbox, not as a later step. This one habit prevents most of these.
Authenticate the domain before warming it.
Keep warm-up running after the initial period rather than switching it off once outreach starts.
Track your warm-up seat usage so a new mailbox does not silently fail to start.

FAQ

How long before I can start sending?

Give a new mailbox a few weeks of warm-up before real volume, and keep warm-up running afterwards. There is no single number; a new domain needs longer than a new mailbox on an established one.

Can I send while warm-up is running?

Yes, at low volume, and keep warm-up on. Ramp up gradually rather than switching from warm-up straight to full sending.

Should I turn warm-up off once I am sending?

No. Leaving it running maintains the reputation it built.

Still stuck? Contact Reply support

If these steps didn't solve the problem, the Reply support team can look at your account directly. Open the Reply Help Center and send the team a message.