To use the outgoing filter in conjunction with Office365, you must first create an outgoing user in EuropeanMX. We recommend that you create the user as "Authenticating Domain" and activate the setting "Re-authentication permitted". After you have defined an outgoing user, you must create a transport rule in Office365. To do this, proceed as follows:
Once set up, any traffic that matches your outgoing sender domain should be routed through the transport rule and processed by the filter servers.
Please note that our servers only accept a maximum of 10 connections from your server. This ensures an optimal delivery speed. To prevent that you get the message "421 Too many concurrent SMTP connections from this IP address; please try again later" and the messages are stored in the queue, the connection limit of 10 connections has to be kept.
The hostname of our relays is "relay.europeanmx.eu". Please make sure that you use port 587. If this is not the case, the messages will be rejected and not sent with the error message "550 Relay not permitted!
IMPORTANT: If you use our outgoing filter for your messages, you must change the SPF entry in the DNS settings of your domain. This should look like the following:
v=spf1 include:spf.europeanmx.eu -all