8 Excellent Open Source Email Clients for RHEL 2026
Reviews and comparison of the 8 excellent open-source email clients for RHEL. Screenshots, features, pros/cons, and installation guides.
Prefer one of the clients below? Download and install your favorite, then follow these instructions.
Email Client Screenshots
Mozilla Thunderbird
Mozilla Thunderbird is an open-source email client for RHEL and is written in the JavaScript & C++ programming language. The official description from its website says, "Access all your messages, calendars, and contacts in one fast app."
Balsa
Balsa is an open-source email client for RHEL and is written in the C programming language. The official description from its website says, "Balsa is an e-mail client for GNOME, highly configurable and incorporating all the features you would expect in a robust mail client."
Claws Mail
Claws Mail is an open-source email client for RHEL and is written in the C (GTK) programming language. The official description from its website says, "Claws Mail is an email client (and news reader), based on GTK+..."
GNOME Evolution
GNOME Evolution is an open-source email client for RHEL and is written in the C (GTK) programming language. The official description from its website says, "Evolution is a personal information management application that provides integrated mail, calendaring and address book functionality."
GNUMail
GNUMail is an open-source email client for RHEL and is written in the Objective-C programming language. The official description from its website says, "An email client for GNUstep."
Geary
Geary is an open-source email client for RHEL and is written in the Vala (GTK) programming language. The official description from its website says, "Geary is an email application built around conversations for the GNOME desktop."
KMail (Kontact)
KMail (Kontact) is an open-source email client for RHEL and is written in the C++ programming language. The official description from its website says, "KMail is the email component of Kontact, the integrated personal information manager from KDE."
Sylpheed
Sylpheed is an open-source email client for RHEL and is written in the C & GTK+ programming language. The official description from its website says, "Sylpheed is a simple, lightweight but featureful, and easy-to-use e-mail client."
Email Client Comparison
| Name | Description | Screenshot | Platforms | Language | Website | Wikipedia |
|---|---|---|---|---|---|---|
| Mozilla Thunderbird ⭐ Recommended | Access all your messages, calendars, and contacts in one fast app. | Screenshot |
| JavaScript & C++ | Website | Wikipedia |
| Balsa | Balsa is an e-mail client for GNOME, highly configurable and incorporating all the features you would expect in a robust mail client. | Screenshot |
| C | Website | Wikipedia |
| Claws Mail | Claws Mail is an email client (and news reader), based on GTK+... | Screenshot |
| C (GTK) | Website | Wikipedia |
| GNOME Evolution | Evolution is a personal information management application that provides integrated mail, calendaring and address book functionality. | Screenshot |
| C (GTK) | Website | Wikipedia |
| GNUMail | An email client for GNUstep. | Screenshot |
| Objective-C | Website | Wikipedia |
| Geary | Geary is an email application built around conversations for the GNOME desktop. | Screenshot |
| Vala (GTK) | Website | Wikipedia |
| KMail (Kontact) | KMail is the email component of Kontact, the integrated personal information manager from KDE. | Screenshot |
| C++ | Website | Wikipedia |
| Sylpheed | Sylpheed is a simple, lightweight but featureful, and easy-to-use e-mail client. | Screenshot |
| C & GTK+ | Website | Wikipedia |
Custom domain email hosting
Free email forwarding and custom domain hosting that works everywhere.
Custom Domain Email Address
Establish credibility with you@yourdomain.com – professional email addresses that build trust.
Unlimited Email Accounts
Create as many domain names and email addresses as your team needs, without extra costs.
Generous 10 GB Email Storage
Ample space for all your important communications and attachments. Pay as you go.
Seamless Compatibility & Deliverability
Works flawlessly with Gmail, Yahoo, Outlook, and adheres to all 2026 email standards for optimal deliverability.
Any device
Access your email anywhere
Our professional email solution offers universal compatibility, ensuring you stay connected from anywhere.
- iPhone & macOS
- Android
- Windows
- Any Email Client
All-inclusive features
No additional fees for must-have features.
- 100% Open-Source Software
- Quantum-Resistant Encryption
- Advanced Email Security
- Reliable Email Sending & Receiving
- Email Archiving & Download
- Integrated Calendars & Contacts
- Bounce & Web Alert Notifications
- Developer-Friendly Email API
- Email Encryption & Message Signing
- Encrypted PGP Forwarding
- Intelligent Spam & Phishing Protection
- Email Standards Compliance
- Forwarding & Secure Delivery
- Safe Web Lookups & Data Protection
- Sandboxed Mailboxes
- Self-Hosted Docker Email
- Zero-Knowledge Architecture
- 99.99% Uptime
Simple pricing
Unlimited domains at every tier.
Start with forwarding, upgrade to real mailboxes, then add team controls. Every tier includes unlimited domains.
- Unlimited inbound email
- Spam protection
- 50 MB attachment limit
- Send Mail As with Gmail
- Catch-all email addresses
- Multiple recipients per alias
- Send emails to webhooks
- Regular expression filtering
Limitations: Email forwarding only, which means you cannot send mailEnhanced Protection
Send & receive as you@yourdomain.com
$3/month for unlimited domainsGet you@domain.com- Everything in Free plus:
- Unlimited aliases ($0/user)
- 10 GB pooled storage
- Secure inbox privacy
- 9000+ outbound / month
- Email analytics & insights
- DMARC Reporting
- Send outbound SMTP email
- Developer API access
Best for: Individuals, freelancers, and small businesses- Everything in Enhanced plus:
- Unlimited team members
- Team permission management
- Shared organizational access
- Priority support requests
- Custom recipient verification
Best for: Collaboration across families, teams, and organizationsEnterprise
For education, universities, alumni, healthcare, government, and custom implementations
$250/month for unlimited domainsContact us- Everything in Team plus:
- Unlimited API requests
- Terms of Use exception for 3rd parties
- Dedicated customer support chatroom
- Enterprise contract agreement sent via DocuSign
- Onboarding assistance and real-time engineering support
Frequently Asked Questions
Common questions about plans.
What's the difference between Enhanced Protection and Team plans?
Enhanced Protection ($3/month) is perfect for individuals who need professional email with sending/receiving capabilities, 10GB storage, and API access. Team plan ($9/month) adds collaborative features like team member management, shared organizational access, and priority support - ideal for families, groups, and businesses.
Can I send and receive emails with the Free plan?
No, the Free plan only supports email forwarding. You can receive emails at your custom domain and forward them to your existing email address, but you cannot send emails directly from your custom domain or store emails on our servers.
Who should choose the Team plan?
The Team plan is perfect for families sharing a domain (like @smithfamily.com), small businesses with multiple employees, organizations needing shared email management, or any group that requires collaborative access to email accounts with proper permission controls.
What does 'unlimited domains' mean?
All plans include unlimited domains at no extra cost. Whether you have 1 domain or 100 domains, you pay the same price. This makes our service extremely cost-effective for users managing multiple websites or businesses.
Do you charge per user/alias like other services?
No! Unlike other email services that charge per user or alias, we include unlimited aliases in our Enhanced Protection and Team plans. Create as many email addresses as you need (info@, sales@, support@, etc.) without additional fees.
Can I upgrade or downgrade my plan anytime?
Yes, you can upgrade or downgrade your plan at any time. When upgrading, you'll get immediate access to new features. When downgrading, changes take effect at your next billing cycle, and you'll retain access to paid features until then.
Trusted by millions
Leading organizations and businesses worldwide rely on our secure and reliable email service.
- Government
US Naval Academy, Government of South Australia, Government of Dominican Republic
- Enterprise
Netflix Games, Disney Ad Sales, Fox News Radio, RCD Hotels
- Open-source
The Linux Foundation, jQuery, Ubuntu, LineageOS, Canonical
- Education
Carnegie Mellon, Cambridge, UMD, UW, Tufts, Swarthmore
Ready to join these organizations?
Why people switch
Trusted for the reasons that matter.
The claims this page makes, backed by people with no reason to flatter us, and a receipt you can check yourself.
Private by architecture
Congrats for fully launching Forward Email – a forwarding service for email that doesn't keep logs or store emails, and which works with ARC to ensure signed forwards don't trip email filters 👏. I'm a happy user! ❤️

Migration is a DNS change
Have now switched email forwarding from MailGun to ForwardEmail.net . Simple and painless (and free!). Just some DNS changes, and it just works. Thanks

One inbox for every address
So they made this cool app that forwards email from your own domain to your Gmail inbox. There is even a catch all option, so sales@, support@, etc all goes to your own inbox. Check it out! It's free! forwardemail.net








