#1
:love_letter: A beautiful, fast and fully open source mail client for Mac, Windows and Linux.
18K starsJun 15, 2026 pushproductivity-automationJavaScriptEmail
$ npx skills add Foundry376/MailspringAlternatives
Gromox alternatives for AI agents.
Compare similar skills by workflow fit, trust score, quality, GitHub adoption, maintenance, and install readiness.
Current skill
Gromox
Groupware server backend for the grommunio Distribution, supporting MAPI/HTTP, RPC/HTTP, EWS, IMAP, POP3 protocols, PHP-MAPI bindings, and import from PST/OST/MSG/CDFV2/TNEF, EML/ICAL/VCF, Kopano, Zarafa
70
Quality
76
Trust
243
Stars
#2
Mail-in-a-Box helps individuals take back control of their email by defining a one-click, easy-to-deploy SMTP+everything else server: a mail server in a box.
15K starsMay 24, 2026 pushproductivity-automationPythonEmail
$ npx skills add mail-in-a-box/mailinabox#3
BillionMail gives you open-source MailServer, NewsLetter, Email Marketing — fully self-hosted, dev-friendly, and free from monthly fees. Join the discord: https://discord.gg/asfXzBUhZr
15K starsJun 11, 2026 pushproductivity-automationGoEmail
$ npx skills add Billionmail/BillionMail#4
A Cloudflare-based email service | 基于 Cloudflare 的邮箱服务 | Cloudflare Email 邮箱 Mail
11K starsJun 9, 2026 pushproductivity-automationJavaScriptEmail
$ npx skills add maillab/cloud-mail#5
Leantime is a goals focused project management system for non-project managers. Building with ADHD, Autism, and dyslexia in mind.
10K starsJun 14, 2026 pushproductivity-automationPHPCalendar
$ npx skills add Leantime/leantime#6
Ultimate calendar for your React app.
3.8K starsJul 27, 2026 pushproductivity-automationTypeScriptCalendar
$ npx skills add wojtekmaj/react-calendar#7
Cal-Heatmap is a javascript charting library to create a time-series calendar heatmap
3.1K starsJul 20, 2026 pushproductivity-automationTypeScriptCalendar
$ npx skills add wa0x6e/cal-heatmap#8
The open-source communication infrastructure for agents and products
39K starsJun 16, 2026 pushproductivity-automationTypeScriptEmail
$ npx skills add novuhq/novu#9
The classic email sending library for PHP
22K starsJun 6, 2026 pushproductivity-automationPHPEmail
$ npx skills add PHPMailer/PHPMailer#10
💌 Build and send emails using React
19K starsJun 12, 2026 pushproductivity-automationTypeScriptEmail
$ npx skills add resend/react-email#11
MJML: the only framework that makes responsive-email easy
18K starsJun 12, 2026 pushproductivity-automationJavaScriptEmail
$ npx skills add mjmlio/mjml#12
Thunderbird for Android – Open Source Email App for Android (fka K-9 Mail)
14K starsJun 16, 2026 pushproductivity-automationKotlinEmail
$ npx skills add thunderbird/thunderbird-android#13
Experience email the way you want with Mail0 – the first open source email app that puts your privacy and safety first. Join the discord: https://mail0.link/discord
11K starsMay 26, 2026 pushproductivity-automationTypeScriptEmail
$ npx skills add Mail-0/Zero#14
✉️ Send e-mails with Node.JS – easy as cake!
18K starsJun 15, 2026 pushproductivity-automationJavaScriptEmail
$ npx skills add nodemailer/nodemailer#15
The world's best AI personal assistant for email. Open source app to help you reach inbox zero fast.
11K starsJun 15, 2026 pushproductivity-automationTypeScriptProductivity
$ npx skills add elie222/inbox-zero#16
Low code web framework for real world applications, in Python and Javascript
10K starsJun 16, 2026 pushproductivity-automationPythonEmail
$ npx skills add frappe/frappeHow to choose
When should you switch?
Use an alternative when it has a clearer install path, higher trust score, fresher maintenance, or better platform fit for your current agent stack. Keep Gromox if it already passes your workflow test and repository review.
Next step
Compare top candidates side by side
Open the compare page, test the install commands in a sandbox, and check each repository before using a skill in production.