Pre-warmed domains and inboxes are email assets with established sender reputations, ready to use immediately in your cold email and AI SDR campaigns. This guide explains what they are, why they matter for deliverability, and how they help you reach prospects' inboxes instead of spam folders.
What Are Pre-Warmed Domains and Inboxes?
A pre-warmed domain is a custom email domain (like techgrowth.io) that has already built trust with email service providers like Gmail and Outlook. A pre-warmed inbox is an email account on that domain (like [email protected]) that includes a realistic sender profile—complete with name, avatar, and email signature.
These assets are warmed through a gradual process where email volume increases over time while maintaining positive engagement signals. This builds sender reputation before you ever send your first campaign.
Pre-warmed domains typically include multiple inboxes (5-10 email accounts) so you can rotate sending and avoid triggering spam filters with high volume from a single address.
Why Pre-Warmed Assets Matter
Email service providers evaluate sender reputation to decide whether your emails reach the inbox or spam folder. New domains and email addresses have zero reputation, which means:
Your first campaigns often land in spam
You need to manually warm up for 2-4 weeks before full sending
Low open rates and replies hurt your sender score
Pre-warmed assets solve this by providing email accounts with established trust. This typically results in 90%+ inbox placement rates from day one, compared to 30-50% for brand-new setups.
Using pre-warmed inboxes lets you skip the manual warm-up period and start sending campaigns immediately with strong deliverability.
How the Warming Process Works
Email warming is a gradual process that simulates natural email behavior:
Starts small: Sends 10-20 emails per day from each inbox
Increases gradually: Ramps up volume by 10-20% daily over 2-4 weeks
Generates engagement: Ensures recipients open emails, reply, and mark as important
Maintains consistency: Keeps sending patterns steady to avoid sudden spikes
Pre-warmed inboxes have already completed this process through automated peer-to-peer warming networks, where accounts exchange emails with positive engagement signals.
While pre-warmed inboxes give you a head start, maintaining good sender practices is essential. Personalize your emails, target relevant prospects, and monitor reply rates to preserve your reputation.
Using Pre-Warmed Assets in Acquisity
Pre-warmed domains and inboxes are available directly in the AI Acquisition platform.
In the Cold Email Campaign Agent
When creating a new campaign, the "Domain & Inboxes" step displays available pre-warmed options. You'll see domain names, included inbox counts, and status badges. Select the assets you need, complete your order, and assign inboxes to your campaign sequences.
In the AI SDR
During AI SDR setup, you'll see a "Choose Pre-Warmed Inbox" option. Select from available warmed inboxes to ensure your automated outreach maintains strong deliverability from the start.
Prerequisites
Before using pre-warmed assets, ensure you have:
Acquisity cold email engine activated
A Growth or Enterprise plan subscription
Organization admin permissions
A payment method on file
What Happens After You Order
Once you order pre-warmed assets:
Processing takes 5-30 minutes to complete
Inboxes automatically sync to your account
You can manage and assign inboxes through your campaign settings
Assets are ready to use immediately in new or existing campaigns
You can view your purchased domains and inboxes in the campaign options tab, where you'll see status indicators showing which inboxes are active and available.
Common Questions
Do pre-warmed inboxes guarantee inbox placement?
Pre-warmed inboxes provide a strong reputation foundation, typically achieving 90%+ inbox placement. However, your email content, targeting accuracy, and engagement rates also affect deliverability. Poorly targeted or generic emails can still land in spam.
Can I use my own domain instead?
Yes, but you'll need to warm it manually over 2-4 weeks. Pre-warmed domains are recommended if you want to start sending campaigns immediately without waiting.
How many inboxes do I need?
This depends on your sending volume. As a general rule, send no more than 50-75 emails per inbox per day. For a campaign sending 300 emails daily, you'd need 4-6 inboxes to distribute the load safely.
Related Resources
Cold Email Agent Guide - Learn how to set up campaigns using pre-warmed inboxes
How to Connect Your Instantly Account - Required integration for pre-warmed assets
AI SDR: Automated Email Reply Management - Use pre-warmed inboxes with AI SDR
For best results, combine pre-warmed inboxes with personalized messaging, proper list segmentation, and regular monitoring of your campaign metrics. This ensures you maintain the strong sender reputation your pre-warmed assets provide.