SuperMailOS
SuperMailOS is managed business email on your own domain for small teams. You bring your domain; SuperMailOS runs the mail server and handles deliverability — SPF, DKIM, DMARC, IP reputation, and warmup — so your email lands in the inbox, not the spam folder.
Setup takes minutes: verify your domain with one-click DNS on Cloudflare, DigitalOcean, and other providers (or guided copy-paste on any registrar), invite your team, and start sending. Every person gets a real mailbox; aliases like hello@ and support@ are unlimited and free.
Webmail is as simple as Gmail — threads, instant search, keyboard shortcuts, labels, dark mode — plus IMAP and SMTP for any mail app, and a live deliverability dashboard showing your mail landing.
Flat pricing per mailbox: Pro $3/mailbox/month annually (10 GB, 3 domains), Business $5 (30 GB, unlimited domains), custom at 50+. 14-day free trial, no credit card.
Learn more about SuperMailOS
500Mail by 500apps
5.0 out of 5 stars
(2 Ratings)
500Mail is an email client software by 500apps that provides secure, encrypted, and ad-free emails service used by small enterprises for accessing emails reliably and world-class data security.
The main USP's of 500Mail include providing world-class data security, accessing any device, and providing unlimited mailboxes.
500Mail has an added feature to add multiple domains in a single interface and facilitate access to unlimited mailboxes for particular domains. With 500Mail filters, users can organize their inbox by applying conditions and actions for the incoming and outgoing emails. Signatures at the end of the emails are added to promote your business.
Learn more about 500Mail by 500apps
Mailu
Mailu is a simple yet full-featured mail server as a set of Docker images. It is free software (both as in free beer & as in free speech), open to suggestions and external contributions. The project aims at providing people with an easily setup, easily maintained and full-featured mail server while not shipping proprietary software nor unrelated features often found in popular groupware.
Main features include:
Standard email server, IMAP and IMAP+, SMTP and Submission with autoconfiguration profiles for clients
Advanced email features, aliases, domain aliases, custom routing
Web access, multiple Webmails and administration interface
User features, aliases, auto-reply, auto-forward, fetched accounts
Admin features, global admins, announcements, per-domain delegation, quotas
Security, enforced TLS, DANE, MTA-STS, Letsencrypt!, outgoing DKIM, anti-virus scanner, Snuffleupagus, block malicious attachments
Antispam, auto-learn, greylisting, DMARC& SPF, anti-spoofing
Learn more about Mailu
Greatmail
5.0 out of 5 stars
(8 Ratings)
Dependable cloud based email hosting with spam filtering, antivirus protection, generous storage and webmail. Compatible with Outlook and all other POP3/IMAP clients. High volume SMTP service for responsible senders. Outbound relay service for transactional messages, email marketing campaigns, newsletters and other applications. Dedicated email servers, clustering and multiple IP load balancing for high volume senders. Fixed monthly cost with unlimited sending and reputation monitoring. Greatmail is an email service provider (ESP) specializing in business class email hosting, SMTP hosting and email servers. For ISPs, application programmers and cloud developers, we also provide custom solutions including dedicated IP servers and process specific, load balanced configurations with multiple servers.
Learn more about Greatmail