Side by side
Mail-in-a-Box vs Zimbra Collaboration
Both stand on email server software. Which one you can start free with, which one lets you read the code, and what each costs once you pay.
Free plan APILinuxSelf-hosted+1
Visit Mail-in-a-Box 
Free plan AndroidiPhoneLinux+4
Visit Zimbra Collaboration The facts
| Mail-in-a-Box | Zimbra Collaboration | |
|---|---|---|
| Free plan | Yes | Yes |
| Open source | Not published | Not published |
| Runs on | API, Linux, Self-hosted, Web | Android, iPhone, Linux, Mac, Self-hosted, Web, Windows |
| Lowest paid plan | Not published | Free or on request |
| Plans published | None | 2 |
| Maker | Not published | Not published |
| Website | mailinabox.email | zimbra.com |
| On email server software | #14 of 33 | #18 of 33 |
Alternatives to Mail-in-a-Box Alternatives to Zimbra Collaboration The whole list