> For the complete documentation index, see [llms.txt](https://docs.emaildelivery.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.emaildelivery.com/docs/what-you-need-to-know-before-you-install-velocity-mta.md).

# What you need to know before you install Velocity MTA

- [The ESP Platform IP can't be used with the MTA](https://docs.emaildelivery.com/docs/what-you-need-to-know-before-you-install-velocity-mta/the-esp-platform-ip-cant-be-used-with-the-mta.md)
- [PTR Records and Reverse DNS](https://docs.emaildelivery.com/docs/what-you-need-to-know-before-you-install-velocity-mta/ptr-records-and-reverse-dns.md)
- [Sending Domain and PTR must match](https://docs.emaildelivery.com/docs/what-you-need-to-know-before-you-install-velocity-mta/sending-domain-and-ptr-must-match.md)
- [Google Postmaster Tools](https://docs.emaildelivery.com/docs/what-you-need-to-know-before-you-install-velocity-mta/google-postmaster-tools.md)
- [MTA link domain points to the sending IP, not the ESP IP](https://docs.emaildelivery.com/docs/what-you-need-to-know-before-you-install-velocity-mta/mta-link-domain-points-to-the-sending-ip-not-the-esp-ip.md)
- [How to use Velocity MTA as an SMTP Relay](https://docs.emaildelivery.com/docs/what-you-need-to-know-before-you-install-velocity-mta/how-to-use-velocity-mta-as-an-smtp-relay.md)
