# The ESP Platform IP can't be used with the MTA {% hint style="warning" %} You can't put the IP that's in use by the ESP in velocity-install/conf/ipaddresses {% endhint %} This is a very common oversight that will cause Velocity MTA to fail to start because the same ports are required by the ESP and the MTA. If the MTA and the ESP try to share an IP address, whichever one is started first will block the ports needed by the other one, preventing it from starting. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET 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?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.