In the Mandrill.config() function you're setting process.env.MAIL_URL. In previous meteor versions the MAIL_URL was unpacked and the arguments passed as an object to the SMTP transport. But now that's changed, and so this behaviour produces a MAIL_URL like smtp://foo@bar.com:pass@host:port which breaks Email.send().
In the
Mandrill.config()function you're settingprocess.env.MAIL_URL. In previous meteor versions theMAIL_URLwas unpacked and the arguments passed as an object to the SMTP transport. But now that's changed, and so this behaviour produces aMAIL_URLlikesmtp://foo@bar.com:pass@host:portwhich breaksEmail.send().