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I was hoping not to have to create remote mailboxes for these 95k users, but it looks that's the way to go in this case. Thanks!!
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I was hoping not to have to create remote mailboxes for these 95k users, but it looks that's the way to go in this case. Thanks!!

<div>
I was hoping not to have to create remote mailboxes for these 95k users, but it looks that's the way to go in this case. Thanks gentlemen!!
</div>


I was hoping not to have to create remote mailboxes for these 95k users, but it looks that's the way to go in this case. Thanks gentlemen!!

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We have a Hybrid set up. I have two On-Premise SMTP servers that need to send email to cloud-based users. These users do not have any email contact records On-Prem as they are strictly cloud-based. As the SMTP servers try to send to these cloud-based users, the On-Premise queues are filling up b/c the SMTP servers are pointing to the On-Premise Exchange servers for delivery. We currently use 'tenantName.mail.protectio<wbr />n.Outllook<wbr />.com and tenantName-org.mail.protec<wbr />tion.Outlo<wbr />ok.com for email routing to users that have been migrated to the cloud. (They have On-Prem Remote mailboxes for routing)<br />
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What SMTP settings should the On-Prem SMTP servers use to reach the cloud-based users?
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We have a Hybrid set up. I have two On-Premise SMTP servers that need to send email to cloud-based users. These users do not have any email contact records On-Prem as they are strictly cloud-based. As the SMTP servers try to send to these cloud-based users, the On-Premise queues are filling up b/c the SMTP servers are pointing to the On-Premise Exchange servers for delivery. We currently use 'tenantName.mail.protection.Outllook.com and tenantName-org.mail.protection.Outlook.com for email routing to users that have been migrated to the cloud. (They have On-Prem Remote mailboxes for routing)

What SMTP settings should the On-Prem SMTP servers use to reach the cloud-based users?

On-Premise SMTP Server sending to Cloud-based mailboxes

Exchange is the server side of a collaborative application product that is part of the Microsoft Server infrastructure. Exchange's major features include email, calendaring, contacts and tasks, support for mobile and web-based access to information, and support for data storage.

Exchange

Within Internet message handling services (MHS), a message transfer agent or mail transfer agent (MTA) or mail relay is software that transfers electronic mail messages from one computer to another using a client–server application architecture. A MTA implements both the client (sending) and server (receiving) portions of the Simple Mail Transfer Protocol (SMTP). The terms mail server, mail exchanger, and MX host may also refer to a computer performing the MTA function. The Domain Name System (DNS) associates a mail server to a domain with mail exchanger (MX) resource records containing the domain name of a host providing MTA services.

Email Servers

Office 365 is a group of software plus services subscriptions that provides productivity software and related services to its subscribers. Office 365 allows the use of Microsoft Office apps on Windows and OS X, provides storage space on Microsoft's cloud storage service OneDrive, and grants 60 Skype minutes per month. Office 365 includes e-mail and social networking services through hosted versions of Exchange Server, Skype for Business Server, SharePoint and Office Online, integration with Yammer, as well as access to the Office software. All of Office 365's components can be managed and configured through an online portal; users can be added manually, imported from a CSV file, or Office 365 can be set up for single sign-on with a local Active Directory using Active Directory Federation Services.