Use Microsoft 365 Mail with extern Hosting

Question

Hello

I have a rookie question:

We have a Domain hosted at Swizzonic. We also have a external Hosting for the website.

I want to do the following:

Host my Website at my External Hosting, receive emails with the external hosting, but also use 1 (really only 1) email from microsoft 365 for my business use. How do I go with that? How can I use 2 mail servers with 1 Domain, is that even possible?

Thank you in advance!

Answer 1

Hello Epic Recruitment,

simplified answer: it is not possible to use two mail servers for one domain and route one e-mail address (eg. user1@example.com) to Microsoft 365 and another e-mail address (eg. user2@example.com) to your external hosting company.

If you can explain in more detail, what you're trying to do with M365 and/or your externally hosted mailboxes we might be able to provider more input.

More detailed/technical answer: You might have seen examples where people configured two e-mail servers for their domain, using multiple MX records. This is usually done for resiliency, eg. failover in case one e-mail server is unavailable or load balancing if you receive massive amount of emails.

But even if you have configured multiple e-mail servers in your MX record, an inbound e-mail to your domain will only be sent to one of those servers.

It is also possible to send outgoing e-mails from more than one e-mail server. A common case for this are newsletter providers, eg. your company sends "regular" e-mails from Microsoft 365 and marketing/newsletter campaigns from another service provider.

Answer 2

not going into to much details...

1. so you want primary mail to be received to Swizzonic, so the your mx record with lowest number (highest priority) should point to Swizzonic hosted mail server, which you surely have, so not change here
2. on Exchange Online/365 side you need to validate your domain to be able to accept its email
3. in DNS don't forget to add SPF record for 365 and DKIM if you intend to send email from 365 also
4. you want to receive email address to exchange online but you do not want to use @<tenant>.onmicrosoft.com?
   1. in your hosting provider email settings you need to set accepted domains to 'Internal relay' and create a connector for unknown recipient email to be send to 365 (contact Swizzonic support on how to achieve this) - probably to 365 mx
      
      1. but for 1 email only you could just forward email received to Swizzonic mailbox and forward it to 365 mailbox via @<tenant>.onmicrosoft.com (secondary/routing email address) while 365 mailbox primary email address is of your domain

this is basic info to get started, final solution depends on your additional objectives and requirements

regards