Built-in email warmup
On this pageWhat it is
What it is
Email warmup is a routine that builds a mailbox's sending reputation before and during outreach. The tool sends a small, rising number of messages between mailboxes in a network, opens them, replies and rescues them from spam, so mailbox providers see normal, wanted activity. For example, a new domain bought for outbound might warm up for a few weeks before it sends any prospecting emails. Dedicated products such as Lemwarm, MailReach and Warmy.io focus on this, and sequencing tools such as Instantly, Lemlist and Smartlead include it.
Why it matters
A new or quiet mailbox that suddenly sends hundreds of cold emails looks like spam to Gmail and Outlook, so messages land in junk or get blocked. Warmup protects the deliverability of the domains you rely on. You need it when you start outbound on a new domain or mailbox, or restart after a long pause. You can skip it if you send a few one-to-one emails a day from an established mailbox, or if a separate service already warms your mailboxes. Warmup does not fix a bad list, weak copy or missing authentication such as SPF, DKIM and DMARC.
What to check
- Does warmup keep running alongside live campaigns, or only before the first send?
- How many mailboxes are covered, and is there a cap on warmup volume per mailbox?
- Does the tool report inbox placement or spam rates, so you can see whether warmup is working?
- Can warmup slow down or pause when a mailbox starts to show deliverability problems?
Tools with Built-in email warmup
Runs multichannel cold outreach with built-in email warmup, lead database, and deliverability scoring.
Sends high-volume cold email across multiple mailboxes with automated warmup and a unified reply inbox.
Automates outreach across email, LinkedIn, calls and SMS to coordinate your sales prospecting in one place.
Run cold email outreach at scale with unlimited mailboxes, warm-up automation and lead verification.
Builds sender reputation for new email accounts by warming them through a network of real inboxes.
Finds and verifies professional email addresses and sends cold email sequences from one workspace.
Warm up mailboxes and test campaigns for spam filters to ensure cold outreach reaches inboxes.
Automate email, phone and LinkedIn sequences to run cold outreach campaigns from a single dashboard.
Automates email warmup and monitors deliverability across domains and IP addresses to reach primary inboxes.
Warms up new email accounts and monitors sender reputation to improve inbox placement for outreach.
Outbound tools without built-in email warmup
Prospects on LinkedIn with automation, scraping and a Kanban CRM all in one focused workspace.