Laravel Mail to Log

I have my Laravel Mail driver setup as to print to my log file:

'driver' => env('MAIL_DRIVER', 'log'),

When I send mail, however, I am receiving a swiftmail authentication error:

Expected response code 250 but got code '530' with message '530 5.7.1 Authentication required'

vendor\\swiftmailer\\swiftmailer\\lib\\classes\\Swift\\Transport\\AbstractSmtpTransport.php

line 383\">AbstractSmtpTransport.php line 383

530 5.7.1 Authentication required

Is there another setting I need to set somewhere? Why is it trying to use swiftmailer?

via Vranvs