There seems to be a recent uptick, and not only in the NVDA group, of topics being split because whatever "takes a look at incoming email" before it lands in your inbox is adding things like, "[SUSPECTED SPAM]," in front of the original subject line. This causes topics to be split, sometimes multiple times.
Messages from any group to which you subscribe from any email service, not just Groups.io, are by definition not spam. You don't get these messages unless you've asked for them.
I am asking anyone who uses this sort of software to please add nvda.groups.io into their whitelist of allowed domains (or whatever terminology your specific product uses to say, "If this message originates from this place, don't classify it as spam.") If you have other groups.io subscriptions you may just want to add any domain that ends in groups.io. Also do this for any other subscription email services you're using. This prevents incorrect spam classification and unintentional topic splitting.
Brian - Windows 10 Pro, 64-Bit, Version 20H2, Build 19042
Any idiot can face a crisis. It's the day-to-day living that wears you out.
~ Anton Chekhov