I finded right steps that how to configure MTA on VSX gateway working on Gaia R80.10. Right steps see below:
1. Activate MTA on VS0, via activation TE and TEX blades.
2. On VS0 in MTA policy, install as domain * and as next hop, your real mail server, in Advansed settings of MTA, install listening on All Interfaces, it's need per design.
3. Activate MTA on VS1 for example, install as domain (yourdomain.com) as next hop, your real mail server, in Advansed settings of MTA, install listening on All Interfaces, it's need per design.
4. Install polisy.