You can configure the SendGrid account as an SMTP relay for notification settings if you want Veeam Backup for Microsoft 365 to send email notifications about backup job results.
Today, I am going to show you how to use SendGrid as SMTP relay at Sophos UTM firewall and help you send email out successful, the Sophos UTM firewall and exchange servers are VMs of Nested Hyper-V host at Azure, if you don’t know how to build a Nested Hyper-V host in Azure, you can reference our Building Real Word lab in Azure Volume 1 book from https://leanpub.com/buildingrealworldlabsinazurevolume1) , this is step by step to tell you how to build your own lab in Azure.
When you try to send email out from exchange server VM at Azure, you will notice it will failed send email out. Because starting on November 15, 2017, outbound email messages that are sent directly to external domains (such as outlook.com and gmail.com) from a virtual machine (VM) are made available only to certain subscription types in Microsoft Azure. Outbound SMTP connections that use TCP port 25 were blocked. (Port 25 is primarily used for unauthenticated email delivery.), so you will notice the exchange server VM won’t send email out after you configure send connector.
As we know, starting on November 15, 2017, outbound email messages that are sent directly to external domains (such as outlook.com and gmail.com) from a virtual machine (VM) are made available only to certain subscription types in Microsoft Azure. Outbound SMTP connections that use TCP port 25 were blocked. (Port 25 is primarily used for unauthenticated email delivery.), so you will notice the VM at Azure won’t send out email.