How do unique emails work in a web application?

Question

Email

On many resources, it is possible to send a letter to a unique (automatically generated) email, upon receipt of a letter to which the site will perform some actions. For example, it will create a message on behalf of the user who owns this unique mailbox.
Question: how does it work? The connection between the web application and the mail server is not very clear.
A simple solution: cron to check mailboxes for new mail, but this solution is too slow and not scalable.
Maybe the mail server somehow notifies the web application about new letters?
And how does the web application create these mailboxes on the mail server?

Answer 1

And how does the web application create these mailboxes on the mail server?

This is called "domain mail". There is one address, for example [email protected] And all letters that came to non- existent addresses of the same domain are redirected to it.

Answer 2

for example mailin.io

Answer 3

Dig here, in Google more details
sanasol.ws/2013/11/16/%D0%BB%D0%BE%D0%B2%D0%B8%D0%...
sanasol.ws/2014/02/07/%D1 %81%D0%BD%D0%BE%D0%B2%D0%...

Answer 4

mailgun.org can do this
. And yes, you check the mailbox by cron and execute