Cheat sheet with all Ports and rules needed for a Exchange Hybrid Infrastructure

Exchange Hybrid Ports Cheat Sheet

When working with Exchange I sometimes come to clients who already have a hybrid exchange configured environment. In many cases this is when the hybrid configuration does not work. To make things easier for myself, I created an overview that eliminates the pain of firewalls and networks.

To help you guys out in these situations i share my ports overview document with you, The document is mentions as a cheat sheet this means that you can adjust it and present it to the customers network team.


There are always some requirements for a Exchange hybrid environment

  • External IP for a seperate Hybrid flow that resolves to
  • You need to be sure that the hybrid server is part of the mail environment
  • Make sure autodiscover is set the right way
  • The Exchange server which is used for the Hybrid configuration needs to be in the LAN
  • Do NOT forget the Exchange online and Exchange online protection URL’s
  • If you do not have an external IP use the external IP of the autodiscover.
hybrid exchange ports cheat sheet
hybrid exchange ports cheat sheet


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2 thoughts on “Cheat sheet with all Ports and rules needed for a Exchange Hybrid Infrastructure

  1. Hi

    Forgive me but why do you need 587? Where ever I have been it is 25,443 between exchange hybrid server and O365 URLs/IPs.

    587 is needed if you setup relaying to accommodate something like printers/scanners on premise so they can relay thru exchange online.

    Thank you

    1. Port 587 is an alternative Client communication for the default port 25. It make sure the clients can communicate thru the hybrid. Most of the time 25 is enough but sometimes 587 is also needed.

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