Greatmail offers email hosting solutions suitable for businesses looking for reliable and secure email services. While it does not specifically mention OS X Server compatibility, Greatmail's email hosting supports cross-platform access, including compatibility with popular email clients on macOS, such as Apple Mail and Outlook.
The service is available in two editions: the Standard Edition, which provides basic email hosting features, and the Groupware Edition, which includes advanced synchronization of mail, calendars, and contacts across devices using Exchange ActiveSync. Greatmail emphasizes security with features like encrypted connections, spam and malware protection, and compliance with industry standards.
For businesses seeking to host email at their own domain, Greatmail provides a fully managed private cloud service, allowing for multiple domain management from a single admin panel. If you're specifically looking for OS X Server email hosting, you may want to confirm compatibility with your existing setup, but Greatmail's offerings appear to be a viable alternative for macOS users.
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