NimblyMail Overview

NimblyMail is a modern email delivery and logging plugin for WordPress. It replaces the default wp_mail() transport with a reliable, configurable mailer and gives you full visibility into every email your site sends.

Key Features

• Nine email providers — route mail through PHP Mail, SMTP, Gmail OAuth, Outlook / Microsoft 365 OAuth, Amazon SES, Resend, SendLayer, Brevo, or ZeptoMail without touching code
• Comprehensive email logging — every outgoing email is captured with recipient, subject, status, send duration, and optional body storage
• Background queue — defer wp_mail() calls to a non-blocking queue powered by Action Scheduler, with three-tier priority, exponential backoff retries, and admin retry/cancel tools
• Developer Sandbox — prevent staging or local environments from sending real email. Capture-only Log mode or Redirect-everything-to-a-safe-address mode, plus an allowlist for testing addresses
• Deliverability Health Audit — automated SPF / DKIM / DMARC / PTR audit of the active sender domain, mailer-aware, with scheduled checks and human-readable findings
• Email controls — selectively disable WordPress notification emails across eight built-in categories
• Failure alerts — receive an alert email via PHP mail() whenever a delivery attempt fails, bypassing the broken transport
• AES-256 credential encryption — stored passwords and API keys are encrypted at rest using AES-256-CBC with HMAC-SHA256 integrity verification
• Settings lock via constants — define constants in wp-config.php to lock settings and make fields read-only in the admin UI
• WordPress Multisite — first-class network support with a Network Admin surface, per-site overrides, and field-level network locks
• Setup wizard — a guided first-run experience that detects existing SMTP plugin configurations and offers one-click import

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Where to Start

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Requirements

Requirement	Minimum Version
WordPress	6.0 or higher
PHP	8.0 or higher
PHP OpenSSL extension	Any version (required for credential encryption)

Tip: Check your PHP version in WP Admin > Tools > Site Health > Info > Server. If OpenSSL is missing, contact your host to enable the php_openssl extension.