Most spammers know about that trick, and their software automatically strips the + and anything after it. Their software has been doing that for about 20 years already, sadly. The + trick really only works with people you trust already. Also, + addressing is in the RFC, so pretty much every mail server supports it.

Gmail also added . (dot) as a non-counted character, so you can put as many of those as you want into the user field, but most spam software is catching onto that too.

My plus addressing with gmail is strictly a whitelist. Anything sent without a plus address is immediately deleted with an automatic filter. The issue I encounter is services that (incorrectly) treat a plus address email as invalid, preventing sign ups.

I use a different delimiter (using the option recipient_delimiter in postfix on my mailserver) and have yet to see a spammer figure it out. YMMV.

That works great if you control your own mail server, but most people don't these days. :)

The reason for this is of course that it's a complete pain to work with the large email providers (say, you want to send an email to gmail) if you have your own service. Email has been far from truly decentralised for a while now.

It's not that bad really. Been doing it since more than a decade.

If you enjoy the administrative work that comes with it (removing yourself from "you exist and you are therefore banned" blocklists, trying to convince gmail/hotmail/etc that you're really a real person, etc) then yes, it's not hard. If you use email, want it to work and don't enjoy extra administrative duties on top of your day job, I'd say it is that bad.

For non-important stuff I can recommend mailhero.

I have also been using mailhero.io since it has first been mentioned on HN.

Lately I do however have issues with mails not being forwarded / blocked at the service. I contacted the developer but as of today no feedback. Obviously this is a free service, which also means that I sadly cant rely on it. I am willing to pay for such a service and will try Maskmail / Othermail, but actually I would prefer an open source solution on an own (micro-)server...

As a spammer, wouldn't it be trivial to just run a regex on email lists looking for that pattern and then harvesting the results? Or is this like the old joke where you don't have to outrun the bear, just your friend?

Well, one more reason not to use gmail i suppose. If you have your own mailserver you can configure a different delimiter.

Sure, but then you get 100 other problems that come with self-hosted e-mail servers that might not be worth the hassle.

At least some years ago this did not work out so well due to broken email validators that did not accept + in the address.

Some sites and systems won't accept email addresses with a plus sign in them - I've found most do tho.