using own domain for mail with Office365, while retaining non-Office365 mailboxes

Question

I have a domain www.somename.nl

I use the domain for a self-hosted website, and for email. Until now, the email was provided by the hosting provider and it was being used via their webmail portal and via pop3.

I started a trial for office 356 for business. Initially I got a email address from them in the format firstname@lastname1.onmicrosoft.com . I of course rather want to use my email address in the format firstname@somename.nl

It seems that for that I need to change some DNS records, as mentioned in this manual: https://support.office.com/en-us/article/Create-DNS-records-for-Office-365-at-any-DNS-hosting-provider-7b7b075d-79f9-4e37-8a9e-fb60c1d95166

In that manual, they mention

When you update your domain's MX record, all new email for anyone who uses your domain will now come to Office 365.

That's certainly not what I want. I only want to migrate my own email to office365, there are a few other users on the domain that should be able to continue using their mail the way they are used to.

Luckily, for that ms also has a manual: https://support.office.com/en-us/article/Pilot-Office-365-with-a-few-email-addresses-on-your-custom-domain-39cee536-6a03-40cf-b9c1-f301bb6001d7?ui=en-US&rs=en-US&ad=US

unfortunately, I get stuck at this piece of the manual;

Instead of creating a new SPF record, add include:spf.protection.outlook.com to your existing SPF record.

SPF record: “v=spf1 mx include:adatum.com include:spf.protection.outlook.com ~all”

in my DNS configuration, there is no SPF record. I'm afraid I will break mail for the other users if I just change it.

Following the manual, I got to this screen, where I'm asked to change the DNS records. In the screen there is once more the warning that this will change mail for all users in the domain (it's in dutch, but you'll get the idea):

any idea where I should go from here?

Answer 1

1. Regarding the SPF record: The page you posted it self has a lot of articlese on how to create reocrds using different DNS providers, look for your DNS provider and follow the steps as mentioned here: https://support.office.com/en-us/article/Create-DNS-records-for-Office-365-when-you-manage-your-DNS-records-b0f3fdca-8a80-4e8e-9ef3-61e8a2a9ab23.

If for some odd reason your DNS provider doesn't support SPF and SRV records, then your best option is to forward the DNS zone to Microsoft or change the location of your zone to another DNS provider.

2. Regarding the warning page: the page you posted say "Do not create a new MX record or change your existing MX record." just follow through with it to the last step. If for some reason the setup didn't allow you to proceed until the DNS verification is complete, then work on modifying the MX record and then let the verification process finish. Once verification is complete, restore the MX record the way it was so emails go back to the old mail server.

3. Suggestions?: if this is all for testing purposes, the experience of using Office 365 is not much different than using the default format firstname@lastname1.onmicrosoft.com, it's not worth the trouble to test a few emails with your current domain name. Another suggestion is to test a different domain name entirely and save yourself the trouble of changing your current setup if you're not too sure of what you're doing.