Help with Email & Changing Name Servers/Webhost?

You should be able to cutover with minimal-to-no downtime (email is generally pretty smart; if the domain is unavailable, remote clients will retry a couple times before giving up). MX records are especially important here as they tell email servers where emails should go (TXT are also important as some of these are used to verify you are who you say you are when sending emails). Assuming you copy everything from the old DNS manager to the new one exactly, there should be no need to reconfigure anything on Google Workspace.

Once you have all the DNS records copied over from Wordpress to BlueHost, updating the nameservers to point at BlueHost should keep everything working consistently. Do double-check your configuration after updating the nameservers (then again after a few hours, it can take time to propagate across the internet).

This tool from Google Admin Toolbox is very useful for checking DNS configurations, it's essentially a web version of the dig command-line tool. If you put the domain in there, you should be able to validate that the MX records match what you expect, then check the NS records to make sure they point at BlueHost. If the NS records still point at Wordpress that probably just means it's still propagating and you should check back later.

In the future, I'd suggest using a third-party service to manage your domains like Dynadot, Porkbun, or Cloudflare (no special love for any of the three, but I've used them all before. They all offer the same basic set of features). IMO it's just a good way to hedge your bets in case you want to quickly change from a bad webhost.

I don't know about BlueHost specifically, but generally, when transferring a domain name to a different provider, it has the option to keep your existing DNS records. You should make sure that the records are transferred, especially the ones that have the type MX or TXT, as those are usually the ones needed for email to work.

If you do that, nothing should break and she would be able to use her email through Google Workspace the same way she does. Domains and DNS are weird though, so while it should be fine, there may be a bit of downtime while the name is being transferred. There isn't anything you can do about that, DNS is a pretty janky system so it can sometimes be unreliable. Though most likely there will be no downtime, and even if it happens, it's going to be a few hours max.

We've transferred the domain, but the nameservers are still registered to wordpress.com. I've found the guides for transferring nameservers on BlueHost and wordpress.com, but this is a step above what I've dealt with in the past.

Can you elaborate on what you mean by "transfer the domain"? Do you mean you've initiated a domain transfer from WordPress.com to bluehost?

That step is probably not, strictly speaking, necessary. You can purchase your domain through one entity and have everything else (even the DNS) running through another.

Quick primer:

• domain registrar - this is who you pay to "own" the domain (originally WordPress come in your case). The main thing they do is provide a configuration for you to say which DNS provider serves the authoritative DNS record for your domain.
• DNS provider - they serve the authoritative record / "master copy" of the DNS records for your domain. Most domain registrars will also provide this service, but there are other providers, like Amazon Route 53 and Cloudflare.
• web host - they run the server that provides your web content to a browser (pictures, text, ecommerce transactions) when people visit your website
• mail host - they run the servers that talk to other mailservers to send and receive email.

You DNS provide is the place where a lot of this transition gets handled.

If you don't change DNS providers, you could leave the domain registration and DNS with WordPress come, and just go into WP's DNS configuration tool and point your A record to bluehost to get the domain live for the website hosted at bluehost. In that case, also you shouldn't need to do anything to the email. It will remain pointed at the gmail servers.

If you've already started transferring the domain to bluehost, you will need to use them as your DNS provider (or configure a third party once the transfer is complete). In either case, you should ASAP copy all the DNS MX and TXT records from the old DNS config to the new one.

During the transition from one DNS provider to another, there may be some time when people resolve the old server or the new one. If they are both configured for Google email, everything should go where it is supposed to. If any mail fails to deliver, most mail servers will hold it for a day the retry delivery. So you shouldn't lose much, if anything.

In the future, i would try to get your domains transferred to a reliable registrar and operate them from there. I have been using namecheap for years and been happy with them. Namecheap can also do the DNS, but I use cloudflare for DNS. It's free for the basic stuff, which is all you need. By having those parts separate from the host and email provider, it's easier to make changes to the hosting and email provider as needed.

Aside from MX, you'll need to copy the SPF, DKIM, and DMARC records. As long as both nameservers are serving the same content then there will be no downtime when switching to the new nameservers.

One thing to note: eg. if you are sending mail from a server like self-hosted wordpress, and you are migrating that to a new server you'll want to switch that over in the SPF record. This might show up as an ip4:169.254.0.0 or something like that, if 169.254.0.0 is the old server IP address then replace that with the new IP address.