[smcleod]

You can also do things like a wildcard on a subdomain like [e-mail].

Otherwise subaddressing with + works well with most mail hosts other than Microsoft Exchange / Office365 (which have had endless problems).

[amadeusw]

That's the way to go. I set up a rule where everything going to *@a.mydomain.com goes into a folder which I largely ignore. Every website gets a unique prefix, e.g. [e-mail].

The advantage of Masked Emails is that third parties won't even know about mydomain.com. The disadvantage is that you need 1Password to recall which email address you used with a particular website.