Folderly vs Warmup Inbox
Side-by-side from the Top 11 ranking of GlockApps vs Validity vs Mail-tester: 11 Best Email Deliverability Tools 2026. Last verified June 15, 2026.
The short answer
Folderly ranks higher on Top 11 (#5 vs #11) for Email marketers and developers improving inbox placement rates. A specialized platform for fixing deliverability problems common in cold email campaigns.
At a glance
| Folderly | Warmup Inbox | |
|---|---|---|
| Top 11 rank | #5 / GlockApps vs Validity vs Mail-tester: 11 Best Email Deliverability Tools 2026 | #11 / GlockApps vs Validity vs Mail-tester: 11 Best Email Deliverability Tools 2026 |
| Score (out of 9.4) | 8.3 | — |
| Best for | Fixing cold outreach deliverability | Proactive reputation building |
| Pricing | $$$ ($200 to $2000/mo) | $ ($19 to $199/mo) |
| HQ | Wilmington, USA | Wilmington, USA |
| Founded | 2019 | 2020 |
Folderly
A specialized platform for fixing deliverability problems common in cold email campaigns.
folderly.com/See full entry in GlockApps vs Validity vs Mail-tester: 11 Best Email Deliverability Tools 2026
Warmup Inbox
A unique tool that automates the process of warming up new email accounts to build sender reputation.
www.warmupinbox.com/See full entry in GlockApps vs Validity vs Mail-tester: 11 Best Email Deliverability Tools 2026
Methodology and scoring weights live at /methodology. No vendor pays for placement — see about.