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SMTP Relay in Office 365?

Zion Phil
Zion Phil asked
Last Modified: 2017-03-08
I have a vanity domain with 4 email addresses hosted with FatCow. Only 1 of the email users has a new Office 365 Premium Business account. Mail from FatCow is forwarded to their assigned *.*onmicrosoft.com account for Office 365 so that the emails arrive in the OFFICE 365 INBOX (OWA MAIL) and then synchronized across their platforms. The Office 365 user can email to any address outside their vanity domain, but when they try to email the other emails on their domain they get the message below.

Error Details
Reported error:      550 5.1.10 RESOLVER.ADR.RecipientNotFound; Recipient not found by SMTP address lookup
DSN generated by:      CY1PR14MB0331.namprd14.prod.outlook.com

This is because, the vanity domain is not in Office 365 as OFFICE 365 is not hosting the email, it is hosted by FatCow. The domain has been verified in Office 365 just so that i can send email out with the reply address of the vanity domain.

I need to see if there is a work around or ability to create an SMTP relay so that when the Office 365 users emails out from Office 365 (exchange) it doesn't just try to look for the same domain emails ONLY in Office 365, but sends out maybe through an SMTP to the FatCow email server.

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MASEE Solution Guide - Technical Dept Head
Most Valuable Expert 2017

HI ZionTech1,
Please try to delete that particular entry and enter again.
Sajid Shaik MSystem Admin

regardign the issue with Exchange 2010 SP3 Hybrid deployment with Office 365 assuming your environment

the most of the issues with AD sync with office 365 ...whch you'll find the detailed description in the following



all the best
Most Valuable Expert 2015
Distinguished Expert 2019
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