* [Duet](https://duetapp.com/) `⊘ Proprietary` - Invoicing and project management with an integrated client portal ([Demo](https://duetapp.com/demo/#dashboard)) `PHP`
## Self-hosting Solutions
## Self-hosting Solutions
* [Axigen](https://www.axigen.com/mail-server/free/) - `⊘ Proprietary` Great alternative to open source. It's a turnkey messaging solution, perfect for small & micro businesses, integration projects or test environments.
* [Axigen](https://www.axigen.com/mail-server/free/) - `⊘ Proprietary` Great alternative to open source. It's a turnkey messaging solution, perfect for small & micro businesses, integration projects or test environments.