To send cold emails that will land in the inbox, you need two things:
- Inboxes – Email accounts your cold emails are sent from.
- Automation Software – This software helps you manage multiple inboxes and automate sending, so you don’t have to do it manually.
Together, they help you send cold emails that book meetings.
The Difference
Aerosend gives you high deliverability inboxes. It handles inbox creation, warm-up, and domain reputation so your emails are ready to go and land in inboxes.
Smartlead and Instantly don’t create inboxes. They take the inboxes you already have and automate the sending, scheduling, follow-ups, and personalization.
That brings us to the key difference between these platforms. Aerosend focuses on the behind-the-scenes infrastructure. It includes inboxes, IPs, Warmup, and servers. Smartlead and Instantly, on the other hand, focus on automating sends, personalization, segmentation, etc.
Understanding this split is the first step to building a cold email system that actually scales.
How does Aerosend work with Smartlead and Instantly?
Aerosend inboxes connect directly to any sequencer (Smartlead or Instantly). You just have to buy domains; we set it up, connect it to your sequencer of choice. Smartlead deals with domain rotations, tags, sending times, etc. Two work together for optimal deliverability.
Here’s how they compare:
| Tool | Core Role | Best For | Why It Matters in Cold Email |
|---|---|---|---|
| Aerosend | Private infrastructure (DNS, inboxes, deliverability) | All teams who want to send cold emails that land in the inbox. | Creates inboxes that are used for domain rotation so teams can continue booking meetings. |
| Smartlead | Sequencer and automation platform | Agencies wanting advanced multi-step sequences, personalization, and AI-driven follow-ups | Automates sending and replies at scale, using Aerosend’s infrastructure for better deliverability |
| Instantly | Sequencer with a simpler UI and fast setup | Solo operators or small teams that need quick campaign launches with basic automation | Offers an easy-to-use sequencer that integrates with Aerosend’s inboxes for instant sending power |

27 Oct 2025
