Apollo.io
ZoomInfo
Lusha
Hunter.io
Instantly.ai
Clearbit
Snov.io
lemlist
Folderly
Loops.so
Mailwarm
Warmup Inbox
Warmbox.ai
Warmy.io
MailReach.co
Resend
Folderly is more than just an email deliverability tool.
Deep email deliverability fixes, technical setup, access to an up-to-date deliverability score, user-friendly template management, team accounts, and, now, spam trigger detection with best practices to followโall of these features assist you in reaching and maintaining 99.9% email deliverability.
Locate, solve, and prevent email deliverability pitfalls, and ensure your emails reach the Inbox folder. Never again let your emails be part of the 51% of all business emails that never reach the inbox. Make every email count, bringing in revenue and business opportunities.
How will you use Folderly?
Reach the recipients' Inbox. Folderlyโs advanced algorithms analyze your outbound email campaigns and identify issues that cause your emails to be filtered out of recipients' inboxes.
Increase delivery, reply, and conversion rates. We will identify the most pressing issues by analyzing your entire email ecosystem and suggest the simplest ways to address them.
Skyrocket revenue from email outreach. By delivering 100% of your emails, you can significantly boost your sender score, generate more leads, and ultimately increase your email channel's ROI.
Apollo.io FolderlyFolderly is recommended for marketers, email campaign managers, and businesses that heavily depend on email as a primary communication tool, especially those who experience issues with emails being marked as spam. It is also suitable for businesses looking to optimize their outreach efforts and improve overall email deliverability rates.
We use Apollo with our Sales and BDR team to manage our cold outreach. The strength of the platform is the sequences and cadences that you can set up. Compared to other tools we have used in the past like Salesloft the UI is much easier to navigate. The main limitation is that the quality of data isn't as vast and often I can find prospects on Linkedin but not in Apollo.
Our field of work requires extensive communication via email; therefore, we needed a solution that would monitor our email deliverability rate and help us eliminate any possible issues causing our emails to land in spam, if they arise. Folderly performs its job well and protects our email reputation. The team has helped us fine-tune our email infrastructure, and is overall very responsive - they always answer our questions in a timely and detailed manner.
With Folderly, we have a clear picture of the situation with our mailboxes, understand what exactly caused our emails to go to spam, and see our campaigns' performance getting better. The team is always ready to give us a helping hand and explain what we need to do next.
We thought our email campaign is doing good, but Folderly team boosted results to super cool! They are always there to help and give insightful advice. If you have troubles with spam and want to improve your email deliverability, Folderly would be your best choice ;-)
Apollo.io might be a bit more popular than Folderly. We know about 69 links to it since March 2021 and only 60 links to Folderly. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
Personal email domains destroy this. Clearbit's Enrichment API returns a null company when it hits gmail.com. Apollo routes personal domains straight to a consumer bucket and skips B2B fields entirely. Even PDL's /person/enrich endpoint โ the most permissive of the major providers โ gives you around 32% hit rate on Gmail addresses versus 74% on corporate domains. I measured this across 6,200 signups for a... - Source: dev.to / about 2 months ago
A few things worth flagging: PDL beats Clearbit's historical rates for US and Western European companies, but drops to ~52% match rate for Japan and South Korea specifically. Apollo underperforms on raw company matching but returns significantly more contacts per domain in Prospector-style queries than Clearbit's Prospector ever did โ the tradeoff is more stale titles in the result set. Hunter.io is fast and cheap... - Source: dev.to / about 2 months ago
One thing comparison guides consistently get wrong: Clay is not an enrichment API. It's a waterfall orchestration tool that calls People Data Labs, Apollo, Clearbit, and others in sequence for you. It's useful, but it adds 2โ8 seconds of latency per row in my runs and costs more per match than going direct. For a CRM webhook flow where you need sub-second enrichment calls, Clay is the wrong layer to hit first. - Source: dev.to / 2 months ago
Last year I ran the same LinkedIn Sales Navigator export through three enrichment APIs. Apollo matched 61% of the emails. Hunter.io matched 54%. An OSINT-first pipeline I'd built in n8n โ pulling from public sources before hitting any paid API โ matched 79% and cost roughly $0.003 per contact. The delta wasn't magic. It was sequence. - Source: dev.to / 3 months ago
Despite having its LinkedIn Page removed in 2025, Apollo remains a functional enrichment and outreach platform with 275M+ contacts. The free tier includes 10,000 credits and the $49/month basic plan is the cheapest entry point for a combined enrichment-plus-sequencing workflow. Apollo's data collection methods have attracted LinkedIn's attention, but the product continues to operate. The risk I'd assign it:... - Source: dev.to / 3 months ago
Make โข Build and automate workflows InvoiceBerry โข Online invoicing for small businesses Gusto โข Payroll, benefits and HR management Hive โข Manage tasks, workflows and teamโs work Lanva โข Social video editing app. ClickUp โข Manage tasks, docs, chat, goals and more Plausible โข Open-source privacy-friendly web analytics Podcast Hawk โข Podcast guest booking software. Writesonic โข AI-driven content... Source: over 3 years ago
BTW, the same thing I noticed with emails. I recently started to work with them, and differentiating emails and sending them to the right group of people brings a more positive outcome. We recently checked it on https://folderly.com/. So, I think those things can be linked to each other. Source: almost 4 years ago
Finally, I would suggest you also use https://folderly.com/ in addition to those two email clients. I would help you avoid making your emails spammy and maintain a high email deliverability score. Itโs essential if youโre using email for business purposes. Source: almost 4 years ago
Besides, I recently noticed that Apple mail didnโt send my emails. I thought my clients didnโt receive my emails because they were in the spam folder. But, I checked my email deliverability on https://folderly.com/, and it was OK. So, Iโve been looking at what makes my clients not get my emails and discovered that this email client doesnโt send them for some reason. Source: almost 4 years ago
But, after testing my email campaign on my friends, I was left puzzled why my letters went to spam. I've read somewhere that you can run all your emails before launching the marketing campaign on https://folderly.com/. I did it, and my score wasn't the best, nor too low. I thought the reason might be in the attached PDF file and links to my store. Do you think that it might be the case? If yes, what are the... Source: almost 4 years ago
ZoomInfo - ZoomInfo is a B2B database providing detailed business information on people and companies.
Loops.so - We bought a billboard in Times Square and we're letting you advertise your startup on it!It's free.
Lusha - Search less. Sell more.
Mailwarm - Email warmup tool to avoid spam folder, since 2020 - Backed by Email Deliverability Experts
Hunter.io - Find all the email addresses related to a domain
Warmup Inbox - Warmup Inbox is a tool that automates the process of warming up your email inboxes, raising your sender reputation and inbox health automatically.