Yeah, this one was interesting. It looks like microsoft updated their TLS stack to TLS 1.3, but incorrectly, breaking TLS connections to Go TLS servers. I don't know how to contact Microsoft about it, but others have raised issues with Microsoft. Mox got a workaround (disabling session tickets for SMTP) so Microsofts TLS stack wouldn't abort the connection anymore. This is a downside of being a small guy: You have to work around the bugs of the big guys.
Absolutely, if you feel that the software is already usable and is not lacking essential features, i'd suggest dropping the second zero in the current version number.
I noticed the roadmap section on your "Features" page, that also helps. I consider SIEVE server side filtering to be pretty essential.
Yes, assuming you mean addresses like user+<anything>@domain. The "+" is configured by default when you add a new domain. See https://www.xmox.nl/config/#cfg-domains-conf-Domains-x-Local....
> Also, with a version number starting with 0.0. I'm left wondering if Mox is already stable enough to be entrusted with my precious email.
It's been suggested to just increase the version number since it's more stable than a 0.0.X might suggest. I'm currently considering mox at release number 14. I'm still on the fence about it. Ideally people make the decision on the merits of stability, not based on the looks of the version number. But I understand it's used as a signal for how stable software is (but mileage will vary!).
At least I'm trying hard not to break anything, so upgrades will work for all installations.