Alexander Huynh via mailop <mailop@mailop.org> wrote:- >Meaning that domains `outlook.com` and `mail.alokind.com` have managed to use >Exchange >365 infrastructure to try and route email through my connector.
As a thought (probably wrong) could this be caused by your O365 users forwarding INCOMING email to them FROM outlook.com and/or mail.alokind.com to external addresses? >My questions are: > > * Is this expected? Whilst not being an expert, probably not. > * Are there any safeguards in place from preventing one tenant from using > another > tenant's connectors? It is not certain that this is what is occurring. For example, your setup would not preclude other tenants pointing their outgoing email to your Exim (not that this would be sensible for them). > * (!) `outlook.com` was somehow routed to my connector, how did that happen? > * What are the suggested methods for preventing other tenants from using > connectors > with IP allowlists (i.e. are domain allowlists the way to go, are there > other > methods)? You may wish to have some authentication between O365 and Exim. The MS document linked discusses how to do this with certificates. If authentication is implemented and messages flow, one knows that the use of the connector is intentional from the O365 end. -- Best wishes, Matthew _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
