For a quick hack, just change the second 'direct' to 'sendmail' in line 17.
For a real patch, change the name in the array, too (rename the first direct to sendmail), and then change it in line 118, too.
I'm switching from Mandrill to Amazon SES. There is an option to send using SMTP.
I wasn't able to find an up-to-date version of the Amazon SES plugin that works with NodeBB >= 1.
Similarly, based on the Git issues, it looks like the emailer-local and emailer-ssl-smtp plugins also aren't compatible?
What are you guys using for SMTP?