Microsoft, for example, for a Windows login account does this.

ah! the fathers of slop vibe code: copy paste coders.

the "validate email input regex" that mistakenly rejects plus sign have been copy pasted for so long it might live on forever.

Could be by design. They want you using your main gmail address and not signing up multiple times.

you'd think if that was the only thing broken on that copy-pasted-regex.

I use PurelyMail to get email redirection with wildcard support. Costs $4/year when I use it with Gmail for the actual storage.

I use an underscore so my addresses look like evidlo_[placholder]@example.com

So they don't charge for emails if they are forwarded? Do you have a link where they describe underscore aliases?

I use their "Advanced" billing mode which is usage-based and ended up cheaper than the fixed-price "Simple" mode. This was my bill for last month (received ~300 emails):

    Total: $0.35
    Storage (GB/month): 0.00 ($0.00)
    Emails sent to non-Purelymail accounts: 19 ($0.00)
    Emails sent: 19 ($0.00)
    Emails sent (GB): 0.00 ($0.00)
    Yearly account fee (days): 30 ($0.33)
    Shared-domain user fees: $0.02

They don't actually support wildcards, but there's a matching pattern "Any address starting with" for which I just entered "evidlo".

https://purelymail.com/docs/routing

No need for a filter rule apparently!

https://purelymail.com/docs/features

"Subaddressing allows you to tag the email addresses you give out. […] This also works with [email protected] (in fact, everything after the first symbol- anything not a letter- in an address is ignored for routing) […]"