The ability to create an email alias is very handy to arrange that emails from specific contacts reside in their appropriate Inbox. For example credit card notifications might be sent cc793xyz@fastmail.com and a `rule' (instruction) ensures their correct storage.
NOTE: this technique hides your normal email addresses.<p>I use and recommend Fastmail. <a href="https://www.fastmail.com/" rel="nofollow">https://www.fastmail.com/</a>
I have a personal email address that’s only used for family or close friends. I then create a different email for each website using email alias. This way if I start to receive unexpected emails on one alias, this alias is probably in hands of a spammer and so I disable it. With this setup I rarely have spams and avoid leaving the same fingerprints on the Internet which is good for privacy.