Citadel Alternatives [Page 3]

Simple, easy and secure mail server with a convenient and simple interface.

The magma server daemon is an encrypted email system with support for SMTP, POP, IMAP, HTTP and MOLTEN

Ensure healthy website performance, uptime, and free from vulnerabilities. Automatic checks for SSL Certificates, domains and monitor issues with your websites all from one console and get instant notifications on any issues.

Try for free freemium $9.0 / Monthly (Lite plan)

MailEnable is a Windows based mail server and email server program that is packed with the state of the features and functions like antivirus and spam filtering system, webmail management system, cardDAV, CalDAV and much more.

Easily and securely connect devices to the cloud.

CyberX's: the only ICS cybersecurity platform built by blue-team cyber-experts with world-class expertise defending critical national infrastructure.

Open-Xchange Server 6 is the most advanced Linux based Groupware solution f.

With Nextcloud enterprises host their own secure cloud solution for storage, collaboration & communication from any device, anywhere.

Open Source

Third party hosting for Microsoft Exchange services.

Sharing & communication software for business

Full featured email server built in docker with free plan.

qmail is the name of an advanced level of mail transfer agent for the UNIX based operating systems.

Definition of millennia from Dictionary.com, the world’s leading online source for English definitions, pronunciations, word origins, idioms, Word of the Day, and more.

Electric Imp is a platform providing WiFi and cloud-based internet connectivity services to all electrical devices.