Setting up Gmail on Spring Boot is supposed to be a snap!  And it is, mostly.

We had a Spring Boot project setup with version 1.3.0 working with email.  When we upgraded to 1.4.2 tears started to flow, but not for long.

The first obstacle you will face is setting your  Gmail account to accept less secure apps.  I won't go into that here - there are heaps of guides on the interwebs, go duck duck go it.

If, however, you are having this ominous error message: 

Failed messages: com.sun.mail.smtp.SMTPSendFailedException: 530 5.7.0 Must issue a STARTTLS command first.

...we may be able to help. First, though, you need to say the magic words!

spring.mail.properties.mail.smtp.starttls.required=true

Well, in my case this was the minimum I needed in my application properties file.

spring.mail.host = smtp.gmail.com
spring.mail.username = javascriptlover@gmail.com
spring.mail.password = j@v@scr1ptR0ck3
spring.mail.properties.mail.smtp.starttls.required=true

That should do it!  I hope that is helpful.

(p.s Before you get too excited, that password is completely made up and is not my opinion of Javascript.)