Does javax.mail work on lan only

javax.mail is a Java API for sending and receiving email, and it can work on both local area network (LAN) and wide area network (WAN) environments.

When using javax.mail to send or receive email, the API uses the Java Mail Transport Protocol (SMTP) to communicate with email servers. This means that the API can send and receive email over the internet, as long as the email servers are accessible and configured correctly.

However, there are some scenarios where javax.mail might only work on a LAN:

1. Firewall restrictions: If the firewall on your network blocks outgoing SMTP traffic, javax.mail will not be able to send email to external recipients. In this case, you would need to configure the firewall to allow outgoing SMTP traffic or use a different email sending mechanism.
2. Email server configuration: If the email server you are trying to send to is not configured to accept email from your network, javax.mail will not be able to send email to that server. In this case, you would need to configure the email server to accept email from your network or use a different email sending mechanism.
3. Network connectivity: If there is no network connectivity between your Java application and the email server, javax.mail will not be able to send or receive email. In this case, you would need to ensure that your Java application has network connectivity to the email server.

To summarize, javax.mail can work on both LAN and WAN environments, but it may require additional configuration and setup to work correctly in certain scenarios.