spring-mail-starter ignoring spring.mail.* config - email

Question

I have a project using spring-boot and added
the following dependency in my build.gradle:
compile group: 'org.springframework.boot', name: 'spring-boot-starter-mail', version: '1.5.7.RELEASE'
My application.properties contains
SMTP Configuration
spring.mail.host=mail.xxx
spring.mail.port=587
spring.mail.username=donotreply#xxx
spring.mail.password=xxx
spring.mail.properties.mail.smtp.auth=true
spring.mail.properties.mail.smtp.starttls.enable=true
spring.mail.properties.mail.smtp.from=donotreply#xxx
According to multiple answers here and documentations i found,that should be enought to create the bean with this settings.
I now want to use a mailer in a Service class
#Autowired
private JavaMailSender emailSender;
[...]
#Value("${spring.mail.host}")
private String mailHost;
When i try to send a message using emailSender i get the following error:
Mail server connection failed; nested exception is
com.sun.mail.util.MailConnectException: Couldn't connect to host,
port: localhost, 25; timeout -1; nested exception is:
java.net.ConnectException: Connection refused: connect. Failed
messages: com.sun.mail.util.MailConnectException: Couldn't connect to
host, port: localhost, 25; timeout -1; nested exception is:
java.net.ConnectException: Connection refused: connect
Obviously it is trying to connect to localhost instead of the configured host.
The variable mailHost does contain the correct value, so the properties are read correct.
EDIT:
The autowired class for emailSender is org.springframework.mail.javamail.JavaMailSenderImpl, which seems to be correct to me.

Answer 1

In my case, the reason was that I instantiated the bean myself like this:
#Bean
public JavaMailSender mailSender() throws IOException {
JavaMailSenderImpl mailSender = new JavaMailSenderImpl();
mailSender.setDefaultEncoding("UTF-8");
return mailSender;
}
Not sure why, but that way, it ignores the application.properties. Maybe the reason was, that I explicitly instantiated JavaMailSenderImpl to set a default encoding and possibly that implementation isn't application.properties aware?
However, removing that bean solved the problem.

Answer 2

[FOUND]
A co-worker was working on the same and had commited an incomplete bean definition. That bean was autowired.