Dev tools · alternatives · 2026

24 alternatives to HELO

Debugging and testing your emails has never been easier.

Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. HELO launched in 2020; newer entries below may have overtaken it.

1
FiloMail for macOS▲158
Instantly turn your Mac inbox into a to-do list
2025 · filomail.com · its alternatives →
2
Mailbox for Mac (Beta)▲490
Fly through your email. Now on Mac
2014 · theverge.com · its alternatives →
3
Spark for Mac▲1,058
Beautiful and intelligent email app
2016 · sparkmailapp.com · its alternatives →
4
Debug Mail▲194
Easy-to-use mail server for developers
2022 · debugmail.io · its alternatives →
5
Helo▲103
An independent email API from former Postmark folks
22d ago · helohq.com · its alternatives →
6
Mailbird for Mac▲373
Email the way you like it, now on Mac
2024 · getmailbird.com · its alternatives →
7
Stoop▲368
Like a podcast app, but for newsletters 💌
2018 · its alternatives →
8
Sidemail▲494
Quick & easy email for all your side projects
2018 · sidemail.com · its alternatives →
9
SMTP Debug Tool▲346
Test and debug your SMTP connection, quickly and for free
2023 · smtpdebug.com · its alternatives →
10
Clearout 2.0▲103
98%+ accurate real-time & bulk email verification services
2020 · clearout.io · its alternatives →
11
Loop Email▲257
Emailing for teams: Organize your Inbox into channels 💌
2018 · intheloop.io · its alternatives →
12
Mailbob▲255
A newsletter platform for personal brands/small businesses
2024 · mailbob.io · its alternatives →
13
Heybounce.io▲166
Fast, accurate & secure email validation service
2024 · heybounce.io · its alternatives →
14
KleanMail Free Email Verifier▲177
Emails inboxed, always.
2022 · kleanmail.com · its alternatives →
15
Mail Tester▲309
Test the spamminess of your email
2016 · mail-tester.com · its alternatives →
16
Forage Mail▲306
AI that solves email overwhelm. Not another mail app.
2025 · foragemail.com · its alternatives →
17
Inbox AI▲201
AI-Powered Personal Productivity
2024 · its alternatives →
18
Nexto▲129
AI generated tasks from emails & calls
2024 · its alternatives →
19
Letterloop for iOS▲249
The newsletter for friends, families & teams
2024 · letterloop.co · its alternatives →
20
Hexospark V2▲134
Reach the inbox with personalized emails at scale
2024 · hexospark.com · its alternatives →
21
Cold Email Analyzer by Mailshake▲222
Real-time analysis of email subject lines and copy
2018 · mailshake.com · its alternatives →
22
Astro for Android▲174
Modern email app for Mac, iOS, and Android, powered by AI
2017 · its alternatives →
23
Groupmail▲80
Self-hosted newsletter app for Mac, Windows & Linux
2020 · groupmail.io · its alternatives →
24
ZeroBounce▲163
Email verification platform, 99%+ accurate
2018 · zerobounce.net · its alternatives →

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Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →