You're Comparing Two Different Things
The LeadsForge vs Mails.so comparison breaks down fast because these tools don't compete. LeadsForge finds contacts. Mails.so verifies emails you already have. That's like comparing a drill to a tape measure - both show up on the job site, but they do completely different work.
30-Second Verdict
LeadsForge is your pick if you need to build prospect lists from scratch, especially inside the Salesforge ecosystem. Mails.so is a standalone email validation API - it cleans lists but doesn't generate them. With a 2.1/5 on Trustpilot, there are real trust concerns around everything except the core tech.
What Each Tool Does
LeadsForge - Lead Generation
LeadsForge is a chat-based lead search engine built into the Salesforge stack. Describe your ICP in natural language, and it pulls contacts across multiple data sources using waterfall enrichment - emails, phone numbers, and professional profile URLs, validated before export.
We've tested the search interface, and the natural language approach genuinely speeds up list building compared to traditional filter-based tools (see sales prospecting techniques). You also get lookalike audience discovery, competitor follower extraction, and intent signals. G2 rates it 4.5/5, and a 100-credit free trial lets you kick the tires before committing budget.
Mails.so - Email Verification
Mails.so is an email validation API. It checks whether addresses are real, catches disposable domains, detects catch-all servers, and runs deliverability checks on single emails or bulk lists (more on email bounce rate).
It integrates with Zapier and Make for workflow automation, claims near-100% API uptime, and offers 50 free credits to start. The pricing page displays per-user figures inconsistently, though - a bad look for a tool whose entire job is precision.
Pricing Breakdown
| Tool | Entry Price | What You Get | Cost Per Unit |
|---|---|---|---|
| LeadsForge | $49/mo | 2,000 export credits | ~$0.025/credit |
| Mails.so (Pro) | $48/mo | 10,000 verifications | $0.005/extra |
| Mails.so (Unlimited) | $498/mo | Unlimited validations | - |
| Prospeo | Free tier | 75 emails + 100 ext. credits/mo | ~$0.01/email |
LeadsForge's credit math matters. One email costs 1 credit, but one phone number costs 10. That $49/mo plan gives you 2,000 export credits total, so you're choosing between 2,000 emails, 200 phone numbers, or some mix (if you're building lists from scratch, see how to generate an email list).
Mails.so tiers range from $5/user/mo (Basic, 500 validations) up to $1,899/mo (Enterprise). Here's what caught our eye: their comparison pages show $249 for both 100K and 1M verifications - the same price for 10x the volume - which raises serious questions about pricing transparency. The industry benchmark for email verification sits around $0.004-$0.01 per check, so Mails.so's rates look competitive on paper, but the inconsistencies make it hard to trust what you'll actually pay (related: email deliverability guide).
The core difference: LeadsForge charges for finding data. Mails.so charges for validating it.
LeadsForge charges ~$0.025/credit for lead gen. Mails.so charges again to verify those same emails. Prospeo finds and verifies in one step - 300M+ profiles, 98% email accuracy, 5-step verification built in - for ~$0.01/email. No CSV handoffs, no dual billing.
One tool. One bill. Every email verified before it hits your list.
What Users Say
LeadsForge holds a solid 4.5/5 on G2, with early sentiment skewing positive - particularly from teams already in the Salesforge ecosystem. G2 names Apollo.io as the top alternative, though Apollo's email accuracy (79%) trails significantly behind platforms that bake verification into the data layer (see best sales prospecting databases).
Mails.so is a different story entirely. Its 2.1/5 Trustpilot score from 37 reviews paints a rough picture: unresponsive support, billing nightmares, bulk jobs that freeze mid-run while consuming credits, and accounts banned without explanation. The complaint patterns are remarkably consistent across reviewers who have no connection to each other.
There's a counterpoint. A Reddit user in r/email reported a 96% reduction in invalid signups after adding Mails.so to their signup flow. The core verification tech works. Everything around it is the problem.
What Your Stack Actually Needs
Here's the thing: comparing LeadsForge to Mails.so reveals a gap in your workflow, not a choice between competitors. The outbound pipeline runs lead generation, then verification, then outreach. LeadsForge covers step one. Mails.so covers step two. Neither covers both (map this to a full lead generation workflow).
Skipping verification isn't an option. Bounce rates above 5-10% risk burning your sending domain, tanking email deliverability across every campaign you run (see how to improve sender reputation).
Let's be honest - if you're stitching together separate tools for lead gen and verification in 2026, you're overcomplicating your stack. Platforms that combine both steps eliminate the CSV handoffs, the dual billing, and the catch-all detection gaps that creep in between tools. Prospeo's 5-step verification with catch-all handling, spam-trap removal, and honeypot filtering runs automatically on every record. No second tool, no extra cost (related: spam trap removal).
Mails.so's 2.1/5 Trustpilot score exists because verification-only tools are a brittle link in your stack. Prospeo eliminates that link entirely - catch-all handling, spam-trap removal, and honeypot filtering run on every record automatically. Data refreshes every 7 days, not 6 weeks.
Replace two unreliable tools with one platform trusted by 15,000+ companies.
The Verdict
Already in the Salesforge ecosystem? LeadsForge is the natural fit. It exports directly into Salesforge and the credit pricing is reasonable for teams committed to that stack.
Only need standalone verification? Look beyond Mails.so. The billing complaints and support gaps are too consistent to ignore. Established verifiers with better track records exist at similar price points (see Bouncer alternatives).
Want both lead gen and verification without juggling two tools? One platform, one bill, 98% accuracy - that's the smarter play for anyone evaluating LeadsForge vs Mails.so and realizing neither tool alone solves the full problem.
FAQ
Are LeadsForge and Mails.so competitors?
No. LeadsForge finds contact data; Mails.so validates addresses you already have. They serve different stages of the outbound pipeline and aren't direct substitutes - you'd need both, or a combined platform, to cover lead gen and verification.
Is Mails.so safe to use?
The verification tech works, but its 2.1/5 Trustpilot score flags real concerns - billing issues, unresponsive support, and difficulty canceling. Test with free credits before committing, and avoid annual plans until you've confirmed the product is stable for your volume.
What tool handles both lead generation and email verification?
Prospeo combines 300M+ contacts with built-in 5-step verification at 98% accuracy - find and verify in one step. The free tier includes 75 emails and 100 Chrome extension credits per month, with no contract required.