Jakarta Mail instrumentation

[famaridon]

Description:

Hello,

I am currently using Spring Boot with Micrometer to monitor my application. While most monitoring features work well, I've noticed that email monitoring is not yet supported.

I propose implementing email monitoring similar to how JMS monitoring was implemented. This would provide a more comprehensive monitoring solution for applications that rely on email notifications.

Rationale:

As discussed with the Spring team in this GitHub issue spring-projects/spring-framework/issues/34496, it appears that this feature should be part of Micrometer rather than the Spring Framework.

Thank you for considering this request.

[shakuzen]

Thanks for opening the issue. I think we could have something for this, but it's been a long time since I've used the relevant API, so I don't know immediately what instrumentation would make sense. Would you be interested in putting together a pull request for this?

[famaridon]

Great, I'll work on it this week.

[famaridon]

Hi,

I'm scared to discover that jakarta.mail.Session is a final class and jakarta.mail.Transport is a class. So, I can't use JDKProxy to do the job.

I'm looking for another way to do it. I'm still working on it.

[famaridon]

I believe I can use the Jakarta Mail feature to define a Transport provider. For more details, you can refer to the Jakarta Mail Specification.

Micrometer I can offer a micrometer:smtp://host protocol that enhances the standard SMTP protocol (and the SSL).

However, I'm uncertain about how to obtain the MeterRegistry and ObservationRegistry (SPI provider, Static reference, ...), and how to configure the Convention.

Do you have any suggestions or ideas on how to achieve this?