Jakarta Mail (Angus): HTTP vs SOCKS Proxy Settings
Choose the mail transport’s documented proxy configuration and separate proxy authentication from SMTP authentication.
A proxy challenge occurs before SMTP authentication. Changing the mail password cannot answer the intermediary's login.
| Proxy path in the Angus SMTP provider | Properties |
|---|---|
| HTTP proxy endpoint | mail.smtp.proxy.host, mail.smtp.proxy.port |
| HTTP proxy account | mail.smtp.proxy.user, mail.smtp.proxy.password |
| SOCKS endpoint | mail.smtp.socks.host, mail.smtp.socks.port |
Use the provider table for the deployed transport and its authentication support. These are provider-specific inputs, not arbitrary aliases for another mail library or JVM-wide settings. For a publicly reachable SMTP server where public intermediaries are permitted, the HTTP proxy list offers candidates for the HTTP host and port. Use no proxy user or password for an unauthenticated candidate, and confirm that it allows the actual mail hostname and port; retain the mail account and TLS settings.
In particular, an HTTP proxy username field is not a SOCKS username field. Authenticated SOCKS must fit the actual JDK/socket path. For SMTPS, use the corresponding transport prefix as documented.
Record where the exchange stops: proxy connection, proxy login, mail greeting, TLS or SMTP account authentication. Failure before the greeting has not tested the mail account. Preserve the mail server hostname and TLS verification after selecting the route.