DOCUMENTATION

Revolutionary SMTP Documentation

Route every WordPress email through an authenticated SMTP or API provider, track delivery in a full log, retry failures automatically, and authenticate your domain with DKIM and SPF, all without leaving wp-admin.

Connect a provider

Wire up SMTP or an API sender and pass a test email in minutes.

Providers

Classic SMTP plus SendGrid, Postmark, Mailgun, Brevo and Amazon SES.

Routing & fallback

Send specific mail through specific providers, with retries and fallback.

Email log

Every send recorded with status, headers and one-click resend.

Deliverability

SPF, DKIM and DMARC guidance to keep your mail out of spam.

Hooks & WP-CLI

Steer routing in code and script every action from the command line.

Introduction

Revolutionary SMTP reconfigures the WordPress mail pipeline so every message your site sends goes out through an authenticated provider instead of the unreliable PHP mail() function. It hooks into wp_mail(), so it covers everything: WooCommerce receipts, form notifications, password resets, comment alerts and any plugin that sends mail the standard way.

Beyond routing, it gives you visibility. Every send is recorded in an email log with its status, the provider's response, the full headers and optional open tracking. Transient failures retry with backoff, and you can configure a fallback provider so a single outage never costs you a message.

Tip: You do not need to change any other plugin. Once a provider is connected, every email that flows through wp_mail() is routed automatically, so WooCommerce, your forms and core all benefit at once.

Installation

Revolutionary SMTP installs like any standard WordPress plugin, from the bundled .zip archive or directly from the Revolutionary Plugins hub.

  1. Upload the plugin. In your WordPress admin, go to Plugins -> Add New -> Upload Plugin and choose revolutionary-smtp.zip. Click Install Now.
  2. Activate. A new SMTP menu appears under Settings, and the connection wizard opens on first run.
  3. Create the log table. On activation the plugin creates the email log table and a default routing profile. No manual database work is needed.
  4. Verify your license. Paste your license key under Settings -> SMTP -> License to unlock automatic updates, the unlimited log, retries and routing rules.

Heads up: If another SMTP plugin is active, deactivate it first. Two plugins both filtering wp_mail() will fight over the mailer and produce duplicate or dropped messages.

Connect a provider

The connection wizard gets you from zero to a passing test email in about two minutes. You choose a provider, enter credentials, set your From identity, and validate the connection before anything is saved.

  1. Choose a provider. Pick SMTP for a generic server, or an API provider such as SendGrid, Postmark, Mailgun, Brevo or Amazon SES. API providers send over HTTPS, which is faster and gets past hosts that block outbound SMTP ports.
  2. Enter credentials. For SMTP, supply host, port, encryption and your username and password. For an API provider, paste the API key. Credentials are encrypted at rest and never echoed back into the form.
  3. Set the From identity. Choose the From name and From email applied to all outgoing mail. Use an address on a domain you control, and force it so plugins cannot override it.
  4. Validate & save. Click Test connection. The wizard opens a real session with your provider and reports success or the exact error. Only a passing connection is saved.

Providers

Revolutionary SMTP speaks both classic SMTP and the HTTP APIs of the major transactional senders. Pick whichever fits your host and your volume. API senders are recommended where available because they avoid blocked SMTP ports and report richer delivery events.

Provider Transport What you'll need
Custom SMTP SMTP Host, port, encryption (TLS/SSL), username, password
SendGrid API API key with Mail Send permission
Postmark API Server API token, verified sender signature
Mailgun API API key, sending domain, region (US/EU)
Brevo API API v3 key
Amazon SES API Access key, secret, region, verified identity
Gmail / Google Workspace SMTP An app password, or OAuth via the connect flow

You can connect more than one provider and assign them with routing rules, for example marketing mail through one sender and transactional mail through another.

Test email

The test tool sends a real message through your current configuration and shows you exactly what the provider returned. Use it after every config change so you never discover a broken connection from an angry customer.

The result includes the provider's raw response code, the message ID, and a link to the matching email log entry so you can inspect the full headers. A red result shows the exact failure reason -- an auth error, a blocked port, or an unverified sender -- so you know precisely what to fix.

Routing & fallback

Routing decides which provider sends which message, and what happens when a send fails. A default route covers all mail; you can add rules above it to send specific email types through specific providers, and set a fallback provider for resilience.

  • Default route: the provider all email uses unless a rule matches first.
  • Conditional rules (Pro): match on recipient domain, From address, subject pattern or the originating plugin, and send through a chosen provider.
  • Fallback provider (Pro): if the primary send hard-fails after retries, the message is re-sent through a second provider automatically.
  • Retries: transient failures (timeouts, 4xx responses) retry with exponential backoff, configurable up to five attempts.

Rules are evaluated top to bottom, first match wins. The plugin records which provider and which attempt ultimately delivered each message in the log, so you always know the path a message took.

Tip: Keep transactional and bulk mail on separate providers. A reputation hit from a marketing blast then never drags down the deliverability of your password resets and receipts.

Email log

The log under Settings -> SMTP -> Email log records every message the moment it is handed off, whether it succeeds or fails. This is your single source of truth for what your site has actually sent.

  • Search & filter by recipient, subject, status, provider, date range or originating plugin.
  • Statuses cover sent, delivered, opened, deferred, retried and failed, updated from provider webhooks where supported.
  • Entry detail shows the full headers, body, provider response and the retry history for that message.
  • Resend any logged message with one click, useful when a customer says a receipt never arrived.
  • Export to CSV for any filtered view, and auto-prune old entries on a schedule to control table size.

Log entries respect WordPress capabilities. By default only administrators can view them; grant the revsmtp_view_log capability to give a custom role read access.

Open tracking

Open tracking tells you when a recipient opens a message, by embedding a tiny tracking pixel served from your own domain. It is off by default and entirely optional. When enabled, the log's status moves to Opened the first time the pixel loads.

Because the pixel is hosted on your site rather than a third party, no recipient data leaves your server. You can enable tracking globally, restrict it to certain email types, or disable it per message with a header so transactional mail like password resets stays untracked.

Privacy tip: Open tracking is best reserved for marketing and digest emails. Leave it off for receipts and resets, both for trust and because many clients block remote images on transactional mail anyway.

Deliverability

Authentication is what convinces mailbox providers your mail is genuine. The Deliverability tab inspects your domain and tells you exactly which DNS records to add. Getting these right is the single biggest factor in staying out of spam.

  • SPF authorizes your provider's servers to send for your domain. The plugin shows the exact TXT record and warns if you exceed the lookup limit.
  • DKIM cryptographically signs your mail. The plugin lists the provider's signing record so receivers can verify nothing was tampered with.
  • DMARC ties SPF and DKIM together with a policy. A starter p=none record is suggested so you can monitor before enforcing.

Each record is checked live against your DNS, with a green tick when it resolves correctly. Copy the value, paste it at your DNS host, and recheck. Most domains pass all three within a few minutes of propagation.

Hooks & filters

Developers can steer routing and react to delivery events with standard WordPress actions and filters. Use the revsmtp_mailer filter to choose the provider for a given message at send time -- here we route anything to an internal domain through a dedicated relay:

add_filter( 'revsmtp_mailer', function( $provider, $email ) {
    if ( str_contains( $email['to'], '@internal.acme.com' ) ) {
        return 'relay';
    }
    return $provider;
}, 10, 2 );

Use the revsmtp_failed action to run your own logic when a message hard-fails after all retries -- logging, paging, or pushing to an incident channel. Other commonly used hooks include revsmtp_before_send, revsmtp_delivered, revsmtp_opened, and the revsmtp_log_retention_days filter.

WP-CLI

Every core action is scriptable from the command line, handy for provisioning new sites or wiring delivery checks into a deployment pipeline.

# Send a test email through the active provider
wp revsmtp test you@example.com

# Show the current connection and route summary
wp revsmtp status

# Tail the last 20 log entries, failures only
wp revsmtp log --status=failed --limit=20

# Resend a logged message by its id
wp revsmtp resend 4821

Troubleshooting

Most delivery problems come down to credentials, blocked ports or DNS. Work through these first:

  • Test email fails with an auth error: re-check the username and password, or regenerate the API key. For Gmail you must use an app password, not your account password.
  • Connection times out: your host likely blocks the SMTP port. Switch to an API provider, which sends over HTTPS, or ask your host to open port 587.
  • Mail sends but lands in spam: open the Deliverability tab and add the SPF, DKIM and DMARC records it flags, then recheck until all three are green.
  • Duplicate emails: another SMTP or mail plugin is still active and also filtering wp_mail(). Deactivate it.
  • Sender keeps reverting: a plugin is overriding the From address. Enable Force From in settings to lock your identity for all mail.

Tip: The email log records the provider's exact response on every send. When something fails, open the failed entry first -- the raw error message usually points straight at the fix.

FAQ

Frequently asked questions

Yes. Revolutionary SMTP is the bridge between WordPress and your provider, it does not send mail itself. You bring an SMTP server or a transactional account (SendGrid, Postmark, SES and so on), which keeps you in full control of sending and billing.

No. Mail is sent in the same request WordPress already used to call wp_mail(), and API providers over HTTPS are typically faster than local SMTP. For high volume you can enable the async queue so sends never block a page load.

The log lives in your own database. Credentials are encrypted at rest, and you control log retention, so old entries auto-delete on the schedule you set. You can also disable body logging if your policy requires it.

Yes. On the Agency plan you can configure providers and routing at the network level and let individual sites inherit or override them, with a single log view across the network.

No. The free tier connects SMTP and core API providers, sends test email, keeps a 7-day log and gives you full DKIM and SPF guidance, which is enough to fix most deliverability problems. Pro adds the unlimited log, open tracking, retries, fallback routes and routing rules.

Was this helpful?

Browse the rest of the documentation or see what is included in each plan.

Back to all docs