SMTPAuthenticationError (530 Error: authentication Required) at Sendinblue

llehirgen

I am unable to send transactional email from my Ruby on Rails application, so I checked my application logs and they say Net::SMTPAuthenticationError (530 Error: authentication Required). I am using the sender verified at Sendinblue (say for instance [email protected]), for a domain authenticated at Sendinblue (say fireworks.com).
I decided to use SMTP to send my transactional emails, so I configured config/environments/production.rb as follows:

config.action_mailer.delivery_method = :smtp
host = 'fireworks.com'
config.action_mailer.default_url_options = { host: host }
ActionMailer::Base.smtp_settings = {
:address => 'smtp-relay.sendinblue.com',
:port => '587',
:authentication => :plain,
:user_name => ENV['SENDINBLUE_USERNAME'],
:password => ENV['SENDINBLUE_PASSWORD'],
:domain => 'fireworks.com',
:enable_starttls_auto => true
}

I use dokku in a root server at NetCup.
My SENDINBLUE_USERNAME variable is set to my login email and my SENDINBLUE_PASSWORD is set to my SMTP key value. I tried once, with these values to send an email but failed and received the 530 Error message. The second time I changed the SENDINBLUE_PASSWORD value to my login password, the password I use to log in to my Sendinblue account, but failed again, and my logs say 530 Error message. So two attempts and two failures so far. Has any of you any idea why I encounter this issue? Sendinblue support was not useful so far.

FrankZ

You can set up the relay via sendmail directly by adding the below to your Sendmail M4 Configuration (sendmail.mc)

define(`SMART_HOST',`smtp-relay.sendinblue.com')dnl     
define(`RELAY_MAILER_ARGS',`TCP $h 587')    
define(`confAUTH_MECHANISMS', `EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl     
FEATURE(`authinfo',`hash /etc/mail/authinfo')dnl

and make a /etc/mail/authinfo file with

AuthInfo:smtp-relay.sendinblue.com "U:SENDINBLUE_USERNAME" "I:SENDINBLUE_USERNAME" "P:SENDINBLUE_PASSWORD" "M:PLAIN" all on one line

then run m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf and restart sendmail

EDIT: depending on O/S you may need to yum install sendmail-cf m4