Our company just acquired a new domain name and we're planning to create a brand new website. When the site goes live, we want to switch over the domain as well. Additionally, we need to update everyone's email addresses to reflect the new domain. I'm pretty new to this process and would love some guidance on how to correctly add the new domain to our Microsoft 365 tenant. Should we keep receiving emails from both domains for a while? What are some best practices and potential issues I should watch out for during this transition?
5 Answers
First, add the new domain to your O365 tenant and any spam filtering. Set the new email address for each user, and at your scheduled cutover time (like midnight), switch everyone's primary address to the new one. Hopefully, you have a plan for distributing new email signatures. It’s usually not a big issue unless the web hosting team messes up the redirect! I'd suggest maintaining both domains active for the foreseeable future, as accounts might not get updated right away.
Jumping from zero to a new domain for email can be risky for deliverability. Set up the email first with proper SPF, DKIM, and DMARC records, and slowly introduce a few users to send from the new domain to let email providers recognize it. Establish allow lists with key partners and monitor any impersonation filter settings. Take this slow to build a good reputation from the start!
One tricky part is the changeover timing. If you're relying on a provider for the website redirect, check your DNS settings and lower the TTL ahead of time to around 5 minutes. This will help with quicker updates during the switch. Also, ensure that the redirect supports HTTPS—it's crucial. Plan for a long night because something will likely go wrong, so have backup snacks and drinks ready!
And don’t forget to have everyone on a call during the switch to troubleshoot any immediate issues!
You should set up the new domain and apply an email address policy to assign it as an alias to every user. When you're ready for the cutover, just change it to be the primary address. Just be cautious about why you’d want to remove the old domain; it’s often beneficial to keep it active for a while for continuity.
Make sure to create a new UPN Suffix in Active Directory for the new domain and update all users accordingly. Don’t forget to add the new domain to your O365 tenant and ensure the proxy addresses for the old domain remain unchanged. This documentation from Microsoft can help you out: [MS Docs on Adding Domains](https://learn.microsoft.com/en-us/microsoft-365/admin/setup/add-domain?view=o365-worldwide). Also, check out this resource about preparing your domain for sync: [MS Docs for Directory Synchronization](https://learn.microsoft.com/en-us/microsoft-365/enterprise/prepare-a-non-routable-domain-for-directory-synchronization?view=o365-worldwide).
Definitely, good links! Always best to double-check everything when dealing with domains.
Totally agree. Keeping the old domain helps avoid losing emails during the transition.