I've had some trouble finding the correct settings to to get a Laravel app running on Lando to send its mails to the Lando Mailhog service. Of course, hindsight is 20/20; if I had started out at the official Mailhog documentation, it would probably have been clear in seconds. I didn't, and went from the Learning Laravel site to the Lando documentation site to Google, passing by numerous Stackoverflow articles along the way.
Just to prime that search query for Lando, Laravel and Mailhog, here's what worked:
MAIL_DRIVER=smtp MAIL_HOST=mailhog MAIL_PORT=1025 MAIL_USERNAME=null MAIL_PASSWORD=null MAIL_ENCRYPTION=null