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@superelay superelay released this 02 Jul 16:19
· 3 commits to smta since this release
3.0.0
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Release Notes: SMTA v3.0.0

We are pleased to announce the release of SMTA v3.0.0, a high-performance, modular, multi-threaded SMTP server written in C. This release brings significant improvements in security, operational stability, standards compliance, and web management.

Tested Platform: This release has been fully tested and validated on Ubuntu 24.04 LTS.

Key Features & Improvements

1. SMTP Capability Control

CHUNKING Support (allow-chunking)

Advertises the EHLO CHUNKING extension and enables BDAT command gating.

SMTPUTF8 Support (allow-smtputf8)

Advertises the EHLO SMTPUTF8 protocol extension for UTF-8 address compliance.

2. Reverse PTR Validation (Inbound Security)

check-iprev-inbound

Enforces reverse DNS lookup verification on all inbound SMTP connections.

trace-iprev-check

Logs detailed DNS lookups and verification status for troubleshooting and auditing.

Granular rejection controls:

reject-iprev-check-temperror — Rejects connections on transient DNS failures (e.g. DNS timeouts).
reject-iprev-check-permerror — Rejects connections on permanent DNS failures (e.g. nonexistent domains).
reject-iprev-check-fail — Rejects connections when reverse verification fails.

3. Authentication Security

smtp-max-auth-failure-rate

Limits repeated authentication failures to help mitigate password-spraying and brute-force attacks.

4. Operations & Message Handling

Custom Job ID Prefix (jobid-prefix)

Prefixes generated Job IDs with a custom identifier (e.g. CUST-12345_1712203200) for easier tracking.

Date Header Injection (add-date-header)

Automatically injects an RFC 5322-compliant X-SMTA-Date header into messages missing a Date header, improving interoperability and deliverability.

SMTP Timeouts

smtp-command-timeout — Prevents slow-client resource exhaustion during SMTP command processing.
smtp-data-timeout — Applies timeout protection during DATA/BDAT message transmission.

5. Critical Fixes

Source IP Selection (is_local_ip)

Replaced socket-binding checks with safe, non-intrusive kernel interface discovery using getifaddrs().
Resolves the issue where SMTP servers bound to local IP addresses prevented the monitor thread from validating available VMTAs.
Eliminates the error:

No source IP available for VMTA

Management Logs & API

Enhanced the Management Logs API to parse multiple timestamp formats, including:

Space-separated timestamps
ISO timestamps without seconds
Other common formats

The web management interface now:

Displays the last 24 hours of logs by default.
Uses more robust timestamp parsing and formatting.

6. Packaging

Package Name: smta

Version: 3.0.0

Supported Platform

✅ Fully tested and validated on Ubuntu 24.04 LTS

Dependencies

libc6
libssl3 | libssl1.1
libjansson4
zlib1g
libcurl4 | libcurl3-gnutls
libsqlite3-0

Bundled Evaluation License

SMTA now includes a signed 90-day Trial License (etc/smta/smta.lic.trial) that:

Automatically activates on fresh installations.
Never overwrites an existing commercial license.
Supports up to 5 Virtual MTAs (VMTAs).
Has no message volume limitations.
Works on any supported host (not machine-bound).

Thank you for using SMTA. We appreciate your feedback and look forward to continuing to improve the platform.

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