Port 25 is the default port for incoming and outgoing mail flow. But, it doesn't mean you need to allow port 25 for incoming and outgoing mail to everyone (all). Instead, Exchange Server port 25 should be only accessible from…
A third-party spam filter works perfectly with Microsoft 365 if you configure it correctly. One important configuration you must apply is to lock down the Exchange Online organization and only accept mail from the third-party spam filter. If you don't…
Are you following the course Exchange Hybrid? You know that the Exchange Hybrid firewall ports are required before going further. After that, we can run the Exchange Hybrid Wizard and start migrating mailboxes, sending, and receiving between on-premises and Office…
In the previous article, we did update MX records to Office 365. This time, we will configure outbound mail flow via Office 365 for Exchange Hybrid environments. Doing that will ensure that all emails sent from Exchange on-premises go through…
A new Exchange Server 2016 has been introduced in the organization. The organization does have an Exchange 2010 running. After migrating the mailboxes to the new Exchange Server 2016, an issue was detected. The issue is that the email is…