Java Programming

I've been trying to figure this out all morning.

The system I'm working on can and will be installed on various platforms (windows, solaris, redhat), and it will need to be able to send email. I don't want to have to rely on a smtp server being configured on each machine due to cross platform complexities (and a central smtp server for all to use is not plausible in the targeted infrastructure).

I've come across Apache JAMES, but they make no effort to be modular enough for me to embed only what I need (to simply use SMTP to send mail). There is a project called Aspirin that does exactly this using Apache JAMES, but it has not been updated for 4 years, and looks like not much development had been done on it anyways.

I found SubEthaSMTP, which similarly describes the frustrations I've been going through this morning, that there were no good available embeddable java SMTP servers, so they wrote their own. Unfortunately, this implementation only receives email, and does not support sending.

Any ideas? Ideally I'm looking for a third party lib that can simply be included into our project and act as an sending SMTP server. This is not for high volumes by any means, so if it means that a server needs to be "started" send an email, and stopped, and takes anywhere from 1-5 seconds, that is perfectly acceptable.