That should not be impacted, in fact thats the whole point. tldr; Google is trying to monetize everything, if you have a use case for using personal custom domains then move to google workspace
I use SES for sending + a forwarding service for receiving and the combination works well. Usually my SES bill is a few cents and AWS just waives the bill.
As of a few years ago there's a similar FDA approved ingredient available in the US as BioMin. It works well for me and is cheaper than importing NovaMin.
Biomin also claims that their particles are smaller and therefore more effective at mineralization than Novamin.
Another option for leveling up on toothpaste is using those that contain micronized hydroxyapatite. Options here are Carifree or the Japanese brand Apagard available on eBay or Amazon. Biomin’s formula is proprietary but it might contain hydroxyapatite in part.
I stopped randomly getting cavities after using xylitol gum occasionally and brushing with these various toothpastes, n=1.
There also exist a variety of oral probiotics that claim to rebalance mouth flora away from species that cause cavities.
While no dentist ever told me about any of these options, at least Carifree is starting to market through US dentists.
There's a similar formula available in the US called Biomin that's FDA approved and distributed by Dr Collins. Their fluoridated version isn't FDA approved yet, but it works well for me used 50/50 with an OTC stannous fluoride toothpaste.