I self-host so that I can set the addresses to whatever I want it to be. I use the ISP's server for sending and my own server for receiving (this can be configu

I self-host so that I can set the addresses to whatever I want it to be. I use the ISP's server for sending and my own server for receiving (this can be configured with Exim). Then, if I receive some spam messages, I can delete an alias that I don't want, in order to avoid receiving any messages. (When someone sends to an invalid alias, the SMTP server gives them a 550 error.) (I use Heirloom-mailx for reading, managing, and sending email messages.)