Sparkpost SMTP relay exim configuration

gistfile1.txt

Host smtp.eu.sparkpostmail.com
Port 587
Alternative Port 2525
Authentication AUTH LOGIN
Encryption STARTTLS
Username SMTP_Injection
Password The password is an API key with Send via SMTP permissions. 

Open /etc/exim4/exim4.conf.template and find the following sections:

begin routers

Below it, add these lines:

send_via_sparkpost:
  driver = manualroute
   domains = ! +local_domains
   transport = sparkpost_smtp
   route_list = * smtp.eu.sparkpostmail.com
   no_more

If you have any other smarthost defined with "domains = ! +local_domains" remove that smarthost.

Continue to the next section:

begin authenticators

Below it, add these lines:

sparkpost_login:
  driver = plaintext
  public_name = LOGIN
  client_send = : SMTP_Injection : api_key

Make sure you have no other authenticators with the same public_name (LOGIN).

Continue to the next section:

begin transports

Below it, add these lines:

sparkpost_smtp:
  driver = smtp
  port = 587
  hosts_require_auth = $host_address
  hosts_require_tls = $host_address

Run the command update-exim4.conf and restart exim /etc/init.d/exim4 restart