[SOLVED] Can the Simple Java Mail Mailer instance be reused? Is it thread safe?

Can the Simple Java Mail Mailer instance be reused? Is it thread safe?

I need some clarification about the usage of Mailer class of the Simple Java Mail library, after creating a Mailer instance like:

Mailer mailer = MailerBuilder.withSMTPServer(
        smtpHost,
        smtpPort,
        smtpUser,
        smtpPassword
    ).
    withTransportStrategy(TransportStrategy.SMTPS).
    buildMailer();

I send email with mailer.sendEmail(email).

Can the Mailer instance be reused to send multiple mails? Or I have to create one for every email I want to send? Right now I tested and it seems to be OK to send multiple emails but not sure.

Is it thread safe?

Solution

The documentation of Simple Java Mail explicitly says you can create the mailer once and reuse it many times and that it's thread-safe, specifically the section Configure once, reuse many times:

You can preconfigure a Mailer and use it many times. It is thread-safe.

Additionally it provides forms of Asynchronous parallel batch sending and clustering, which further reinforces its thread-safety. Or at least, if something provides parallel batch sending, I would expect it to be thread-safe, even if it hadn't been declared explicitly.