Kaddora MailFlow SMTP
Secure WordPress email delivery with SMTP and supported provider APIs, encrypted credentials, test email, source-aware logs, and basic reports.
Use with caution
Kaddora MailFlow SMTP works, but test it on a staging site before relying on it in 2026. It runs on 40+ sites and was last updated 1 month ago, and scores 58/100 on our health check.
- Small user base (40+ active installs)
- Very few reviews so far
How does it stack up?
Side-by-side on installs, updates, ratings & supportDaily downloads
Download spikes usually follow a new release β each site that auto-updates counts as a download.
Rankings
Where Kaddora MailFlow SMTP stands todayWordPress.org search rankings
Live position in the plugin search, top 100| Keyword | Position |
|---|---|
| >100 | |
| gmail | >100 |
| >100 | |
| sendgrid | #76 |
| smtp | #90 |
Version adoption
Share of active sites per release.
About Kaddora MailFlow SMTP
From the official readme Β· v1.0.0Description
Kaddora MailFlow SMTP is a focused WordPress email-delivery plugin built around direct provider connections, encrypted credential storage, privacy-conscious delivery logs, source-aware email attribution, and manual Gmail OAuth that does not require a Kaddora-operated relay.
This WordPress.org release includes:
- Other SMTP delivery.
- Gmail API delivery with manual OAuth and PKCE.
- SendGrid API delivery.
- Mailgun API delivery.
- Postmark API delivery.
- Multiple named connections with one active primary connection.
- Encrypted credential storage.
- Guided setup and provider-specific configuration forms.
- Test Email with the configured MailFlow delivery pipeline.
- Basic Email Log with search and status/provider/source/date filters.
- Detailed log view and provider-attempt history.
- Basic 7-, 30-, and 90-day delivery reports.
- Provider performance and source performance reports.
- Source-aware attribution for WordPress, WooCommerce, WPForms, and Contact Form 7 when those integrations are present.
- Basic connection health information and WordPress Site Health integration.
- Privacy-conscious log retention and uninstall controls.
- Privacy-safe system diagnostics that do not expose stored credentials or message bodies.
No Kaddora-operated relay is required. Provider communication is direct between the WordPress site and the email service configured by the administrator.
Additional mailers and advanced delivery workflows are available through separately distributed MailFlow SMTP extensions. These extensions are separate products and are not included in, required by, or used to unlock functionality in this WordPress.org plugin.
Learn about the separately distributed MailFlow SMTP Pro plugin:
https://themekaddora.com/items/kaddora-mailflow-wp-smtp-wordpress-email-logs-gmail-outlook-amazon-ses/1062
External services
Kaddora MailFlow SMTP contacts an external provider only after a site administrator explicitly configures that provider and performs an OAuth authorization, connection test, provider health request, or sends email through it. No email content is sent to Kaddora-operated servers by this package.
Google APIs / Gmail
When Gmail is configured, the plugin connects directly to Google OAuth endpoints for authorization and token refresh and to Gmail API endpoints for account checks and email delivery. During OAuth, Google receives the OAuth client information, redirect URI, requested scopes, authorization code, and token-refresh data required by OAuth. When email is sent, Google receives the sender and recipient addresses, subject, message body, headers, and attachments required to deliver that message. Gmail is contacted only when the administrator configures Gmail or WordPress sends or tests mail through that connection.
Google Terms: https://policies.google.com/terms
Google Privacy Policy: https://policies.google.com/privacy
SendGrid
When SendGrid is configured, the plugin connects directly to SendGrid’s HTTPS API. Provider checks use the administrator-provided API key. When email is sent, SendGrid receives sender and recipient addresses, subject, message body, headers, and attachments required for delivery. SendGrid is contacted only when the administrator configures or tests SendGrid or WordPress sends mail through that connection.
Twilio Terms of Service: https://www.twilio.com/en-us/legal/tos
Twilio Privacy Notice: https://www.twilio.com/en-us/legal/privacy
Mailgun
When Mailgun is configured, the plugin connects directly to the Mailgun US or EU HTTPS API selected in the connection settings. Provider checks use the administrator-provided Mailgun credentials. When email is sent, Mailgun receives the configured sending domain, sender and recipient addresses, subject, message body, headers, and attachments required for delivery. Mailgun is contacted only when the administrator configures or tests Mailgun or WordPress sends mail through that connection.
Mailgun Terms of Service: https://www.mailgun.com/legal/terms/
Mailgun Privacy Policy: https://www.mailgun.com/legal/privacy-policy/
Postmark
When Postmark is configured, the plugin connects directly to Postmark’s HTTPS API. Provider checks use the administrator-provided Server API token. When email is sent, Postmark receives sender and recipient addresses, subject, message body, headers, and attachments required for delivery. Postmark is contacted only when the administrator configures or tests Postmark or WordPress sends mail through that connection.
Postmark Terms of Service: https://postmarkapp.com/terms-of-service
Postmark Privacy Policy: https://postmarkapp.com/privacy-policy
Custom SMTP servers
When a custom SMTP connection is configured, the plugin opens a connection to the SMTP host, port, encryption mode, username, and other settings entered by the site administrator. A connection test sends the minimum SMTP traffic required to verify that configuration. When email is sent, the SMTP operator receives sender and recipient addresses, subject, message body, headers, attachments, and authentication data required by that SMTP service. The SMTP operator is selected by the site administrator, so its terms and privacy policy depend on that operator. The site administrator is responsible for reviewing the terms and privacy policy of the selected SMTP service.
Installation
- Upload the plugin ZIP in Plugins > Add New Plugin > Upload Plugin, or install it from WordPress.org when available.
- Activate Kaddora MailFlow SMTP.
- Open MailFlow SMTP > Settings > Setup.
- Choose a supported provider and configure the required credentials.
- Save and test the connection.
- Make the tested connection primary.
- Open Settings > Email Test and send a test message.
- Review Email Log and Email Reports after live mail is sent.
Frequently asked questions
Which mailers are included in this WordPress.org release?
Other SMTP, Gmail, SendGrid, Mailgun, and Postmark are included and usable in this release.
Are credentials stored in plain text?
No. Provider credentials are handled through the plugin credential vault and encrypted storage.
Does the plugin send data to Kaddora servers?
No Kaddora-operated intermediary is required by this package. Provider communication is direct to the email service selected and configured by the site administrator.
What does the WordPress.org Email Log include?
The WordPress.org Email Log includes basic metadata, status, provider, source attribution, date filtering, detailed log information, and delivery-attempt history. Advanced features such as message resend, attachment archiving, engagement tracking, and log export are not included in this WordPress.org plugin.
What does the WordPress.org Email Reports page include?
The WordPress.org edition provides basic delivery totals, sent/failed counts, success rate, provider performance, source performance, and recent failures for 7-, 30-, and 90-day windows. It does not include open/click tracking, scheduled reports, weekly summaries, or advanced analytics.
Is MailFlow SMTP Pro included in this plugin?
No. MailFlow SMTP Pro is a separate plugin. The Upgrade to Pro page in this plugin is informational and links to ThemeKaddora. Pro functionality is not included in or unlocked from code bundled in this WordPress.org plugin.
Changelog
1.0.0
- Initial WordPress.org release.
- Includes Other SMTP, Gmail, SendGrid, Mailgun, and Postmark delivery.
- Includes encrypted credential storage, guided setup, test email, basic logs, basic reports, Site Health checks, and privacy controls.
For developers
Is this your plugin? Show off the numbers.
Add a live badge to your site, docs or GitHub README. It updates on its own β no account needed.
Best Kaddora MailFlow SMTP alternatives
All email plugins βFAQ
Kaddora MailFlow SMTP: quick answers
Straight answers, pulled from live WordPress.org data.
Live data from WordPress.org Β· checked Sep 28, 2026
Is Kaddora MailFlow SMTP free?
Yes. Kaddora MailFlow SMTP is free to download and use from the official WordPress.org plugin directory.
Is Kaddora MailFlow SMTP safe to use in 2026?
Kaddora MailFlow SMTP works, but test it on a staging site before relying on it in 2026. It runs on 40+ sites and was last updated 1 month ago, and scores 58/100 on our health check.
How many websites use Kaddora MailFlow SMTP?
Kaddora MailFlow SMTP is active on 40+ WordPress websites and has been downloaded 192 times since it launched in August 2026. It was downloaded 124 times in the last 30 days.
Does Kaddora MailFlow SMTP work with WordPress 7.1?
Kaddora MailFlow SMTP is officially tested up to WordPress 7.0.6, while the latest release is 7.1.2. It may still work, but try it on a staging site first.
What PHP version does Kaddora MailFlow SMTP need?
Kaddora MailFlow SMTP requires PHP 7.4 or higher. Most hosts run PHP 8.x today, so it works on any modern WordPress hosting.
When was Kaddora MailFlow SMTP last updated?
The latest version, 1.0.0, was released on August 24, 2026 (1 month ago).
Who makes Kaddora MailFlow SMTP?
Kaddora MailFlow SMTP is developed and maintained by kaddora.
What are the best alternatives to Kaddora MailFlow SMTP?
The most popular alternatives to Kaddora MailFlow SMTP are WP Mail SMTP by WPForms (4M+ installs), MC4WP: Mailchimp for WordPr⦠(1M+ installs) and Easy WP SMTP (500K+ installs).
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