Dissallow sending mails outside the org
Hi, today I´ll explain a very quick and simple process to avoid users from sending messages outside the org using Exchange Online.
First of all, we need to enter our Office365 subscription portal (http://portal.microsoftonline.com) and then access our Exchange Admin Center (EAC) from the upper right side where it says «Admin» and then clicking on «Exchange» (check this out if you have a small business subscription).
Once we´re inside, click on the «Mail flow» section and then on the «rules» tab to create a new transport rule, click on the «+» sign and then on «create a new rule…«.
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Type a name to identify the rule and be able to associate with like «outgoing messages restrictions».
- Click on the bottom part where it says «More options«
- On «Apply this rule if…» select «The sender is this person» and select all users that will apply the restriction.
- Click on «Add condition«
- Select «The recipient is, external/internal«, and «Outside the organization«
- On «Do the following…» select the «Block the message» and «Reject the message and include an explanation» option.
- Specify a message to be delivered as a reason for the blocked users that try to send messages outside the org like «Sending messages outside the org is not permitted» and accept..
- Click on «Save» and we´re done.
Best of all is that we don´t need to create another rule for each user that we want to apply the same behaviour, we just simply have to edit the rule and add the users we want or create a group and add it as a recipient.