MailHog can be used to reliable test sending emails in your local development environment. It catches sent emails and displays them in an own web user interface.
MailHog can be installed without a hassle via brew in macOS.
Installation
You can start the installation via the following command in the Terminal:
brew install mailhog
Code language: Bash (bash)
Start
To start MailHog afterwards, just enter the following command in the Terminal:
brew services run mailhog
Code language: Bash (bash)
You can then access the web interface via http://0.0.0.0:8025, which looks like this:

Every received email can be accessed as if you were in a webmail app.
Catching all emails from PHP
To make sure that every email that is sent via PHP is being catched by MailHog and not being send anywhere else, you should adjust the sendmail_path
in your php.ini. There you can define MailHog as used program to send emails:
sendmail_path = /usr/local/bin/MailHog sendmail
Code language: JavaScript (javascript)
Having not yet picked a side myself I’m curious why you favor brew over macports or nix?
I simply didn’t ever use MacPorts or something else.