Mailu
Mailu is an easy-to-use, yet powerful mail server that comes as a Docker image. It is open source software, which means it's free (as in free beer and free speech), and is open to external contributions. The project aims to provide people with an easily configured, easily maintained, and full-featured email server without shipping proprietary software or unrelated features that are often found in popular groupware.
The main features include:
Standard email server with IMAP, IMAP+, SMTP, and Submission profiles for clients
Advanced email features: aliases and domain aliases. Custom routing
Webmails, multiple access to webmails, and administration interface
User features, aliases auto-reply and 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
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Mailtraq
Mailtraq Professional is a complete email server. It is a complete email server that does everything you require at a low price and without hassles. Mailtraq is a great Microsoft Exchange Alternative. It's easy to install and manage. Mailtraq's low license cost, lack of server-CALs and stability make it the ideal email server software for SMBs and SOHOs. Email is the lifeblood of any company or organization. The location of these messages is crucial to the long-term success of your business. Running your own email server is not without its hassles and costs, but it allows you to control who has access. If you use the service of your ISP, their system administrators will be able to see and read all your messages. If you use SAAS for a hosted service and if using a Cloud provider, you don't only not know who is reading your emails, but you don't even know what country it is stored in.
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Mail-in-a-Box
Mail-in-a Box lets you create your own mail service in just a few simple steps. It's like creating your own gmail that you can control from the top down.
Mail-in-a Box is a cloud computing service that turns a new computer into a functioning mail server. You don't have to be a tech expert to set this up.
Mail-in-a Boxes include webmail, an IMAP/SMTP Server and desktop mail software. It also includes calendar and contacts synchronization.
The box includes standard mail functionality such as spam protection (spam filters and greylisting), email client auto-configuration, mail filter rules, and automated backups via Amazon S3 or other services.
When you choose to let it be your nameserver, the box will also automatically configure DNS records that are important for mail deliverability, security, and other factors, such as SPF, DKIM DMARC and MTA STS. DNSSEC (with DANE TLSA enabled) provides a higher degree of protection when enabled.
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hMailServer
hMailServer for Microsoft Windows is a free and open-source e-mail client. It is used by Internet service provider, companies, government, schools, and enthusiasts around the world.
It can be easily integrated with most existing webmail systems. It offers flexible spam protection based on scores and can be attached to your virus scanner for scanning all incoming and departed email.
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