FastMail offers <i>aliases</i> to do exactly this [1].<p>You can send &amp; receive directly from&#x2F;to your main inbox (you get a dropdown when you send to select your From: address).  You can make 10 aliases with a Full account; it goes up to 600 w&#x2F; higher accounts [2].<p>[1]  <a href="https:&#x2F;&#x2F;www.fastmail.com&#x2F;help&#x2F;receive&#x2F;aliases.html" rel="nofollow">https:&#x2F;&#x2F;www.fastmail.com&#x2F;help&#x2F;receive&#x2F;aliases.html</a><p>[2]  <a href="https:&#x2F;&#x2F;www.fastmail.com&#x2F;help&#x2F;account&#x2F;limits.html" rel="nofollow">https:&#x2F;&#x2F;www.fastmail.com&#x2F;help&#x2F;account&#x2F;limits.html</a>