Downgrade jakarta.mail to 1.6.7 to fix email features

[gaetanmaisse]

Issue

Email service isn't working anymore, doing any action resulting in an email will lead to the following error:

Caused by: org.springframework.mail.MailSendException: Mail server connection failed; nested exception is javax.mail.NoSuchProviderException: smtp. Failed messages: javax.mail.NoSuchProviderException: smtp
	at org.springframework.mail.javamail.JavaMailSenderImpl.doSend(JavaMailSenderImpl.java:448)
	at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:361)
	at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:356)
	at io.gravitee.rest.api.service.impl.EmailServiceImpl.sendEmailNotification(EmailServiceImpl.java:157)
	... 18 common frames omitted
Caused by: javax.mail.NoSuchProviderException: smtp
	at javax.mail.Session.getService(Session.java:874)
	at javax.mail.Session.getTransport(Session.java:804)
	at javax.mail.Session.getTransport(Session.java:745)
	at javax.mail.Session.getTransport(Session.java:725)
	at org.springframework.mail.javamail.JavaMailSenderImpl.getTransport(JavaMailSenderImpl.java:538)
	at org.springframework.mail.javamail.JavaMailSenderImpl.connectTransport(JavaMailSenderImpl.java:517)
	at org.springframework.mail.javamail.JavaMailSenderImpl.doSend(JavaMailSenderImpl.java:437)
	... 21 common frames omitted

Description

JakartaMail 2.x switched to the new jakarta.mail namespace.
So libraries using earlier versions of JakartaMail/JavaMail will not work with it as they need the javax.mail namespace.

Spring 5.x is importing stuff from javax.mail namespace and so cannot be used with JakartaMail 2.x for now.

According to Support for Jakarta EE 9 (annotations and interfaces in jakarta.* namespace), Spring will switch to using the jakarta.* namespace in Spring Framework 6 / Spring Boot 3. For details see: spring-projects/spring-framework#25354

---

📚  View the storybook of this branch here

🚀 CI was able to deploy the build of this PR, so you can now try it directly here
Notes: The deployed app is linked to the management API of the Element Zero team's environment.