Migrating from webmail hosting to On-Premise Microsoft Exchange Server 2016

Question

Migrating from webmail hosting to On-Premise Microsoft Exchange Server 2016

Mohamed Hemida 21

Hi all,

I have a customer who has webmail hosting and wants to move to on premise Exchange Server 2016. I can describe my problem with the design to make a succussed migration as below:

the customer has primary domain name and two sub domains all related with One MX record as a benefit from the hosted site, you will find recipients like John@Company portal .com also you will find ******@fabrikam.contoso.com and finally Albert@sameera .contoso.com and if you tried to make CNAME record and issuing it with the current MX record all the recipients with subdomain UPN will failed to receive any new mails just only John@Company portal .com will receive emails.

Now I want to know the best practice to do with External DNS (ISP) and suitable records to create If I want to make all recipients receive new mails after the migration.

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Answer 1

Eric Yin-MSFT 4,396

Install Exchange with contoso.com, add your subdomains as accepted domain (Authoritative domain), then create MX record that points subdomain.com to your Exchange server.

Another method is used when the number of recipients in all domains is too big for one Exchange server to handle, you create Exchange with contoso.com, add DCs for subdomains and install second/third Exchange server on them with subdomain1.com and subdomain2.com, these subdomains are added to accepted domains automatically and you just need to make all these servers internet-facing, no need to modify MX record then.

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Mohamed Hemida 21 Reputation points

2020-11-17T19:02:15.117+00:00

Hello RricYin

thanks for your support.
1: I get confused so could you give me an example for MX Record and IP mapping .
2: This solution is very good and I like it but for some reasons related to the customer is not applicable.
Mohamed Hemida 21 Reputation points

2020-11-17T19:21:31.52+00:00

There is a scenario I had thought about before asking this question and I want to validate it and find if it is related to what you mentioned before:
Eric Yin-MSFT 4,396 Reputation points

2020-11-18T08:52:40.137+00:00

If Exchange accepts mail for recipients in an accepted domain from the Internet, you need to configure an MX record for the domain in your Internet-facing (public) DNS servers. Each MX record should resolve to the Internet-facing server that receives email for your organization.
You can refer to this thread as an example: https://serverfault.com/questions/669445/mx-server-multiple-domains-on-one-ip
Eric Yin-MSFT 4,396 Reputation points

2020-11-24T09:28:44.25+00:00

I am writing here to confirm with you how the thing going now?
If you need further help, please provide more detailed information, so that we can give more appropriate suggestions.

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Migrating from webmail hosting to On-Premise Microsoft Exchange Server 2016

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