[endisneigh]

Doesn’t seem like a bonus. Your custom domain could just be blocked wholesale. Hide my email uses iCloud, not a separate domain. iCloud addresses probably won’t be blocked as that’s the default email given for hundred million plus Apple accounts.

[resfirestar]

Fastmail by default uses @fastmail.com addresses for masked email, same as their cheapest plan, so when I used it there was never anything blocked except the occasional site that only accepts gmail addresses (yep, they exist). Personally I prefer it that way for personal use, the custom domain sacrifices anonymity, but it might be nice for business users.

[Nextgrid]

Fastmail is still like 0.1% of users. If you're a "growth & engagement" company you're probably better off banning that domain wholesale and as a bonus will get rid of tech-savvy ad/tracker blocker users without making any impact to your target market.

The advantage of iCloud is that it's a domain laymen use - those same laymen the "growth & engagement" scum wants to track and spam. They can't just ban it wholesale without alienating a large chunk of their target market (and a pretty lucrative one at that, since Apple hardware is expensive).

[wartijn_]

A while ago I ran into the first site that told me I couldn't use my fastmail masked email: remove.bg. I don't know if they block every fastmail.com address, or if they somehow check if it's a masked email.

[mantra2]

This is a plus, I’ve noticed the duck.com addresses from DDG are already blocked heavily.

[tpowell]

Really? Where have you noticed this?

[mantra2]

Lots of random weirdness for me trying to use mine. Most recent example was trying to checkout as a guest on Little Caesar’s app. Kept declining my Apple Pay transaction without telling me why — changed the email and it worked.

There’s only been a handful of times I’ve used it, maybe 12? At least a few of those times it wouldn’t even let me submit it saying it was an “invalid email”. Couldn’t even get past the validation.

[saghm]

Any idea if using a custom domain would have worked better here? I wouldn't be surprised if some places only accept email addresses from a small set of "known" providers

[mantra2]

Custom Domains work fine, that’s my primary email. Doesn’t do much for privacy though.

[RockRobotRock]

Any website that uses a library such as this one: https://raw.githubusercontent.com/micke/valid_email2/master/...

[blitzar]

I have a custom domain on simplelogin (protonmail purchased them) that is occasionally blocked (github openai etc are recent examples).

I suspect they validate by looking up the MX record and block it based on the entry containing simplelogin.co

[mynameisvlad]

Companies blocking disposable email domains are doing it to prevent many users from using their service with a disposable email.

A custom domain that only I use specifically for disposable emails would look indistinguishable from any other custom domain out there, and nobody else would have used it for them to even be aware of its existence.

To block it pre-emptively, they’d have to either be omniscient or block every single custom domain in existence. The former I highly doubt is the case, the latter would generally do more harm than good to them.

[RockRobotRock]

Nobody is going to care enough about your domain to block it individually.

[cj]

Was hoping to find an an iCloud email in your profile but instead found this:

> humanity will go extinct March 11th, 2401

Please explain! Citation required :) /s

[jbc1]

Blocking domains that aren't iCloud, gmail, etc would mean blocking business users. Do you know of any services doing that?

[blitzar]

> Do you know of any services doing that?

Microsoft, Google, Apple

[mynameisvlad]

Microsoft and Apple allow custom domain names in MSA and Apple IDs. I have them for both.

I do believe Google requires Workspace to have a custom domain, though.