ProtonMail limits aliases but also allows “catch all” addresses. So for $48/yr you can be you@yourdomain.com and sign up for things using somespammer@yourdomain.com.

Similar to the other reply, (as of writing this comment), zoho also allows setting up a catch all email address using your custom domain.

I’m quite happy with Firefox Relay - I know that they also support custom domains and they are quite affordable. Maybe have a look into it :)

I don’t know about unlimited, but: fastmail.help/…/360060591073-How-to-set-up-aliase…

How many aliases can I have?

Accounts can have up to 600 aliases, plus 15 for every user in the account.

They support catch-all aliases as well, which is in effect unlimited.

I’m working on this for my service, port87.com

I’m making custom domains have two options, single user or multi user. Either way, any user can have unlimited addresses.

Single user:

• address1@example.com
• address2@example.com

These all go into the same user’s account as a label named the same as whatever comes before the @.

Multi user:

• user1-address1@example.com
• user1-address2@example.com
• user2-address1@example.com
• user2-address2@example.com

The custom domain feature isn’t ready yet, but I’m looking to launch it in the next two months. If you’d like to help me test it, I can give you free access in exchange for trying out all of the features and giving me bug reports.

Try Migadu. Almost unlimited domains and aliases, 3GB quota, any number of mailboxes. You pay according to how much mail you send and receive.

mxroute.com. Also fastmail (not literally unlimited but some number in the hundreds I think). But they are on the expensive side.

Fastmail does catchalls through subdomains automatically. So if my fastmail address is xyz@mydomain.com then anything@xyz.mydomain.com will be forwarded to me. So that’s how I assign special addresses to websites and stuff. I don’t know if mxroute does that.

In practice places have gotten less obnoxious about sharing emails. It’s been pretty rare for those addresses to spill across multiple senders.

I can't seem to find a limit with https://addy.io It certainly doesn't tie it to a certain website.

You could go with a regular mailing service that has a catch all feature and the ability to forward emails to your main address. You lose out on all the useful features such as disabling certain addresses and open your inbox to more spam but it’s an idea.

Not gonna outright recommend them in a privacy subreddit but for example Cloudflare has a feature like this from what I can tell and so does Apples paid icloud plans.

Could setup your main address as name@example.com and your catch all with a subdomain such as servicename@mail.example.com and just have them forwarded to the first address

I get that services don’t want to ruin their own email domains, but I should be allowed to do whatever I want with my own domain.

Email works with both domain reputation and IP reputation. Even if you have your own domain you’re still using their IPs for emails, they’re still tied to it for abuse.

I’ve been hosting my own for over a decade, works great and no limits other than what the hardware can do. I’d recommend doing that since you already have a domain.

Almost any basic web host will allow you to create unlimited email addresses and/or aliases for your domain. Most will offer this service with even their cheapest “shared hosting” plans. And if all of the aliases are going to same person, just enable the catch-all mailbox. Why bother with an email-only service at that point?

I’ve been using purelymail.com for quite some time now, am very happy with it.

Tuta does.

I don’t understand. How does the site you’re using the email alias for impact how many aliases you can have? I use simplelogin with a custom domain and have never been restricted from adding an alias. I don’t recognize the issue you’re having.

$0/month for unlimited domains and catch-all aliases (only email forwarding)

$3/month for unlimited domains and aliases for a “single user”

$9/month for teams:

forwardemail.net

Also going to rep purelymail here. Been with them a while and you can really have basically unlimited aliases with custom routing and everything.