Slicey vs Instantly
How Slicey's isolated infrastructure compares to Instantly's shared inbox panels.
Instantly has the best sending platform in cold email. Their campaign builder, lead database, and inbox rotation are all solid. But their inbox infrastructure runs on shared Microsoft panels. Your domains sit alongside other customers' domains. If someone on your panel sends garbage, your deliverability takes the hit. Slicey does the opposite: every domain gets its own Microsoft account, credit card, proxy, and fingerprint. Nothing shared. No domino effect. If you're already using Instantly for sending, pair it with Slicey inboxes for the infrastructure layer.
Feature comparison
| Feature | Slicey | Instantly |
|---|---|---|
| Per-domain isolation | Yes, unique MS account per domain | No, shared panels |
| No domino effect | Yes, domains are fully sandboxed | No, one bad sender can burn the panel |
| Inboxes per domain | 49–99 | 3–5 |
| Free domain replacement | Yes, no questions asked | No |
| White-glove setup | Included | Self-service |
| Built-in sending platform | No (bring your own) | Yes, full cold email platform |
| Lead database | No | Yes, 160M+ contacts |
| Email warmup | Pre-warmed before delivery | Built-in warmup network |
| Deliverability tracking | Real inbox placement tracking | Warmup score (not actual placement) |
| You own your domains | Always | Varies by plan |
| Price | $49/domain/mo | ~$36/domain/mo |
The bottom line
Instantly is a sending platform. Slicey is inbox infrastructure. They work well together. Use Instantly to send, Slicey to land. The isolation is what keeps your domains out of spam when the person next to you on a shared panel gets sloppy.