MailConnectException: Couldn't connect to host, port: smtp.sendgrid.net

I have created API key for sendGrid:

I have following spring mail configuration:

spring.mail.default-encoding=UTF-8
spring.mail.host=smtp.sendgrid.net
spring.mail.username=apikey
spring.mail.password=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
spring.mail.port=25
spring.mail.protocol=smtp
spring.mail.test-connection=true

And I have following code:

MimeMessage message = sender.createMimeMessage();
MimeMessageHelper helper = new MimeMessageHelper(message,
            MimeMessageHelper.MULTIPART_MODE_MIXED_RELATED,
            StandardCharsets.UTF_8.name());
Template template = freemarkerConfig.getTemplate(templateFileName);
String html = FreeMarkerTemplateUtils.processTemplateIntoString(template, props);

helper.setTo("myEmail@gmail.com");
helper.setText(html, true);
helper.setSubject(subject);
helper.setFrom(from);
sender.send(message);
logger.debug("Send email to {} with subject: [{}]", Arrays.toString(to), subject);

Then I try to start application and experience following error:

27.01.18 20:07:20.460 [main] WARN  c.d.m.s.c.MailSenderValidatorAutoConfiguration - Mail server is not available
com.sun.mail.util.MailConnectException: Couldn't connect to host, port: smtp.sendgrid.net, 25; timeout -1
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:2118)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:712)
    at javax.mail.Service.connect(Service.java:366)
    at org.springframework.mail.javamail.JavaMailSenderImpl.connectTransport(JavaMailSenderImpl.java:501)
    at org.springframework.mail.javamail.JavaMailSenderImpl.testConnection(JavaMailSenderImpl.java:382)

How can I fix this?

P.S.

Everything correct for port 587

But I want to use ssl and set port=465

spring.mail.port=465

And at this case my application freezes on startup.and after 5 min prints:

27.01.18 21:06:05.960 [main] WARN  c.d.m.s.c.MailSenderValidatorAutoConfiguration - Mail server is not available
javax.mail.MessagingException: Could not connect to SMTP host: smtp.sendgrid.net, port: 465, response: -1
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:2106)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:712)
    at javax.mail.Service.connect(Service.java:366)
    at org.springframework.mail.javamail.JavaMailSenderImpl.connectTransport(JavaMailSenderImpl.java:501)
    at org.springframework.mail.javamail.JavaMailSenderImpl.testConnection(JavaMailSenderImpl.java:382)

How can I avoid this?

You may need add something like this to your configuration.

spring.mail.smtp.ssl.enable=true

There is a probability that SendGrid SMTP servers are not discoverable in your country. try a proxy or VPN.

I used the port 2525 (Non-privileged) instead of 578 (privileged) to solve the problem locally. I can still use the privileged one on the cloud. That solved my problem.

来源：https://stackoverflow.com/questions/48478360/mailconnectexception-couldnt-connect-to-host-port-smtp-sendgrid-net

标签

java

Spring

smtp

sendgrid