[etothepii]

Personally I use the + feature on email addresses to achieve this.

[e-mail]

Maps to the account me and will (if configured correctly) put the mail in a folder called folder if such exists.

The reason you might want many accounts with the same email seem many to me if you don't realise that you can create arbitrary distinct emails this easily.

[lxgr]

Yes, that's exactly what plus addresses exist for!

It seems to me like all benefits of the "exact same email, multiple accounts" feature are vastly outweighed by the inconvenience for users simply forgetting that they already have an account, and creating a second one by accident that way.

I mean, even I end up almost creating an account by accident every now and then (mostly on sites using the horrible "signup is the default, login needs one additional click" pattern), and I do so using autofill from a password manager!

[dgan]

Unfortunately many services think they are smarter than you, and disallow "+" in email fields

[Nekobai]

Indeed! And even worse, some services will happily accept "+" in email fields, but then some part of the service fails to encode the "+" sign correctly, so some features may be broken in unexpected ways.

Sometimes you can't even contact Customer Services because "your account doesn't exist" (because you cannot feed the correct email address to their customer service site).

Thankfully it's rare, but when it happens it's extremely infuriating.

[xp84]

Just so you know, that plus-hack is by no means universal (in addition to the frustrating “you can’t use a plus sign” thing you’ll encounter at various email fields around the net).

Gmail supports it. Microsoft does not. Neither does Yahoo/AOL. It likely was not widely supported in the 90s either. It’s a nice hack but it doesn’t solve every problem.