Fixed #702: clarified that RecipientBuilder accepts one address, while RecipientsBuilder handles comma- or semicolon-delimited address lists; see the recipient builder examples.

Simple Java Mail 9.3.1 is a Java 8-compatible build-tool maintenance release.

Changes

• Updated Maven Antrun Plugin from 3.1.0 to 3.2.0 for the JPMS consumer-compilation check.
• Updated Maven Dependency Plugin from 3.8.1 to 3.11.0 for construction of the JPMS module path.

These changes affect project build tooling only. This release contains no runtime-dependency changes, public API changes, or intended mail-sending behavior changes. Java 8 remains the minimum supported runtime.

The maintenance pull requests are #700 and #701.

Simple Java Mail 9.3.0 exposes batch-module as a supported standalone Jakarta Mail orchestration API.

• #698 adds BatchTransportExecutor<K> for applications that create their own Session and MimeMessage objects without adopting EmailBuilder or Mailer. The main simple-java-mail facade is not required.
• Register Sessions by cluster key, then run cluster-selected or exact-Session callbacks synchronously or submit them as CompletableFuture work. Each callback receives the actually selected Session and connected Transport.
• The facade keeps raw leases private, releases connections after successful callbacks, invalidates them after escaping failures, resolves OAuth2 credentials from the selected Session, and provides deterministic graceful or forced shutdown. Its default executor is module-owned; an injected executor remains caller-owned.
• The existing pooled Mailer path and the standalone facade now share one transport engine. smtp-connection-pool remains the only physical pool owner; do not stack batch/direct orchestration over the Jakarta smtppool provider.
• The supporting chain is updated to smtp-connection-pool 4.0.1, clustered-object-pool 4.0.3, and generic-object-pool 2.4.2. The published JPMS names are org.simplejavamail.batch, org.simplejavamail.smtpconnectionpool, org.bbottema.clusteredobjectpool, and org.bbottema.genericobjectpool.

See the SMTP connection pooling and batch orchestration guide for the comparison matrix, ownership rules, and complete examples.

Simple Java Mail 9.2.0 adds refresh-aware OAuth2 credentials and includes security, compatibility, and correctness fixes.

• #692: added refresh-aware OAuth2 access-token providers for long-lived Mailers.
• #691: routed all asynchronous send failures through the returned CompletableFuture.
• #690: made serialized emails preserve send-ready content and fail clearly when pre-9.2 streams lack resource data.
• #689: moved governance opt-outs after email starters and removed the faulty pre-start methods.
• #685: corrected extra Jakarta Mail property precedence to system properties, environment variables, then property files.
• #684: corrected the S/MIME configuration example to use a valid message-content cipher.
• #683: moved CLI-only recipient parsing out of EmailPopulatingBuilder without changing CLI behavior.
• #680: made S/MIME signature status represent only verification that actually occurred and preserve failed combined results.
• #679: rejected DKIM configurations that exclude the mandatory From header.
• 55586ee6: added explicit file: and base64: DKIM private-key sources while preserving unprefixed values.
• #678: contained embedded-image auto-resolution within configured file, classpath, and URL bases.
• #677: replaced trust-all TLS defaults with the JVM trust store while retaining hostname verification.
• #676: bound the authenticated SOCKS bridge to JVM loopback instead of wildcard interfaces.

See the 9.2 migration guide for changes requiring source or configuration updates.

Simple Java Mail 9.1.8 is a patch release for proxy routing and connection-pool reset behavior.

• MailerBuilder.usingSession(session).withProxy(...) now updates the supported mail.smtp.socks.* route while leaving the rest of the caller's Session configuration untouched (#686).
• SOCKS proxying now works with SMTPS; implicit-TLS certificate and hostname verification remain unchanged (#687).
• resetConnectionPoolMaxSize() now restores only the maximum pool size, without changing the configured core size (#696).
• resetConnectionPoolClaimTimeoutMillis() now restores only the finite default claim timeout (approximately 24.9 days), without changing connection expiry (#697).

Applications that deliberately relied on the old accidental long-expiry behavior can express it directly with withConnectionPoolExpireAfterMillis(Integer.MAX_VALUE).

Simple Java Mail 9.1.7 fixes recipient selection in the standalone CLI.

• Restores independent --email:to, --email:cc, and --email:bcc options, allowing one command to combine all three recipient types.
• Retains --email:withRecipients for compatible single-recipient-type commands.
• Leaves the public Java builder API unchanged.

Versions 9.0.0 through 9.1.6 cannot combine TO, CC, and BCC this way because repeated --email:withRecipients options are merged into one invalid invocation. CLI users who need multiple recipient types should upgrade to 9.1.7 or later.

See #682.

CLI recipient notice: Versions 9.0.0 through 9.1.6 cannot combine TO, CC, and BCC recipients in one CLI command. Repeated --email:withRecipients options are merged and rejected. Follow #682 for the 9.1.7 correction.

Simple Java Mail 9.1.6 is a patch release for applications using the Spring module.

• spring-module no longer packages its test application.properties. In versions 9.0.0 through 9.1.5, those sample values could override an application's YAML settings; the local-bind test value 192.0.2.30:25259 could then prevent SMTP connections.
• A packaging guard now prevents root application.* and bootstrap.* configuration files from entering the production artifact.

No public API changed, and Java 8 compatibility is retained. If you use spring-module 9.0.0 through 9.1.5, upgrade to 9.1.6 or later. After upgrading, the withLocalBindAddress("0.0.0.0", 0) workaround is no longer needed.

See #681.

Spring-module notice: Versions 9.0.0 through 9.1.5 package test application settings that can override an application's YAML configuration and prevent SMTP connections. If you use spring-module, upgrade to 9.1.6 or later.

CLI recipient notice: Versions 9.0.0 through 9.1.6 cannot combine TO, CC, and BCC recipients in one CLI command. Repeated --email:withRecipients options are merged and rejected. Follow #682 for the 9.1.7 correction.

Simple Java Mail 9.1.5 is a patch release fixing SOCKS5 domain framing in authenticated SOCKS support.

• Domain connect requests now place the two-byte port after the UTF-8-encoded hostname bytes, fixing malformed requests for internationalized and other non-ASCII hostnames (#674).
• Domain-form SOCKS5 replies now decode the hostname after its length octet and read the port after the complete hostname, restoring accurate host and port diagnostics (#675).

Compatibility: this release has no public API changes and retains Java 8 compatibility.

Spring-module notice: Versions 9.0.0 through 9.1.5 package test application settings that can override an application's YAML configuration and prevent SMTP connections. If you use spring-module, upgrade to 9.1.6 or later.

CLI recipient notice: Versions 9.0.0 through 9.1.6 cannot combine TO, CC, and BCC recipients in one CLI command. Repeated --email:withRecipients options are merged and rejected. Follow #682 for the 9.1.7 correction.

Simple Java Mail 9.1.4 fixes file-stream ownership in EML conversion and includes Java 8-compatible dependency and release-tool updates.

Fixes

• EmailConverter.emlToEmailBuilder(File, ...) and EmailConverter.emlToMimeMessage(File, ...) now deterministically close the FileInputStreams they create after synchronous conversion.
• The caller-ownership contract is unchanged: overloads that accept an InputStream continue to leave caller-provided streams open.

Maintenance

• Updated SpotBugs annotations to 4.10.3.
• Updated the Central Publishing Maven Plugin to 0.11.0.
• Updated Objenesis to 3.6.

There are no public API changes. Java 8 remains the minimum supported runtime.

Tracked in #669, #670, #671, #672, and #673. Artifacts are available from Maven Central.

Spring-module notice: Versions 9.0.0 through 9.1.5 package test application settings that can override an application's YAML configuration and prevent SMTP connections. If you use spring-module, upgrade to 9.1.6 or later.

CLI recipient notice: Versions 9.0.0 through 9.1.6 cannot combine TO, CC, and BCC recipients in one CLI command. Repeated --email:withRecipients options are merged and rejected. Follow #682 for the 9.1.7 correction.

Simple Java Mail 9.1.3 fixes Outlook inline-image handling for native-HTML-only .msg files by updating outlook-message-parser to 1.16.2. Inline cid: images are now matched correctly, and trailing NUL terminators no longer leak into attachment metadata.

See issue #668, the upstream fix, and the 9.1.0–9.1.3 release notes.

Java 8 remains the minimum supported runtime.