Title: SMTP Senpai Author: MailSenpai Published: October 12, 2026 Last modified: October 12, 2026 --- Search plugins ![](https://ps.w.org/smtp-senpai/assets/banner-772x250.png?rev=3741400) ![](https://ps.w.org/smtp-senpai/assets/icon-256x256.png?rev=3741400) # SMTP Senpai By [MailSenpai](https://profiles.wordpress.org/mailsenpai/) [Download](https://downloads.wordpress.org/plugin/smtp-senpai.1.1.2.zip) * [Details](https://wordpress.org/plugins/smtp-senpai/#description) * [Reviews](https://wordpress.org/plugins/smtp-senpai/#reviews) * [Installation](https://wordpress.org/plugins/smtp-senpai/#installation) * [Development](https://wordpress.org/plugins/smtp-senpai/#developers) [Support](https://wordpress.org/support/plugin/smtp-senpai/) ## Description SMTP Senpai connects the email your WordPress site sends (password resets, order emails, contact form notifications and anything else that uses `wp_mail()`) to [SMTP Senpai](https://en.mailsenpai.com/smtp-senpai/), the SMTP relay and REST email API by MailSenpai, hosted in the European Union. You need an SMTP Senpai account to send email through it. The plugin itself is free and has no paid features. #### Two ways to send * **API key (recommended)** – each email is sent with an HTTPS request to the SMTP Senpai API. It works even when your hosting provider blocks outgoing SMTP ports. * **SMTP** – WordPress connects to the SMTP Senpai relay (`relay.mailsenpai.com`, port 2525, STARTTLS by default) with your SMTP username and password. Host, port and encryption can be changed. #### Features * Its own **SMTP Senpai** menu: Dashboard, Settings, Test & domain check, Email log and Help. * Dashboard with the state of the connection, the monthly volume of your plan, the latest emails and the result of the sender domain check. * Guided setup in three steps (API key, sender on a verified domain, test email) with a progress bar. * Plain explanations for the common problems (domain not verified, key not valid, account suspended, monthly volume used up, site that cannot reach the service) with a link to the page of the customer area where to fix them. * Admin bar item with a status symbol (check mark: working, clock: setup not finished or account being activated, warning sign: the last email was not sent) and quick links. Only administrators see it, and it can be turned off in the settings. * Replaces the WordPress mailer cleanly through the `pre_wp_mail` filter (API mode) or `phpmailer_init` (SMTP mode). * Supports To, Cc, Bcc (up to 50 recipients per email in API mode), Reply-To, HTML and plain-text emails, attachments (up to 10 files, 10 MB in total) and custom` X-` headers. * Sender address and name, with an option to force them for every email. * Optional fallback to the default WordPress mailer if the API cannot accept an email (off by default). * Send a test email and see the exact answer of the API when something is wrong. * Sender domain check: SPF, DKIM, DMARC and MX in plain language, with what to fix. * Account status box: plan volume, emails used and remaining, SMTP details. * Simple email log (date, status, recipients, subject, error), kept for 7, 14 or 30 days and cleaned up automatically. Message bodies and attachments are never stored. A privacy mode masks the addresses and drops the subjects. * Secrets are stored encrypted, never autoloaded and never shown again in full. You can also define them in `wp-config.php`. * Works on multisite: every site has its own settings and log. * Translation ready. No tracking, no ads, no external scripts or fonts: everything the admin pages need( icons, logo, the Poppins font) is bundled with the plugin. Nothing is shown outside the plugin pages except the optional admin bar item. ### External services This plugin connects to services operated by MailSenpai on `app.mailsenpai.com`. Nothing is sent until you configure the plugin or use one of its tools. **1. SMTP Senpai email API** – `https://app.mailsenpai.com/relay/v1/invio` * What it is for: delivering the emails of your site when the plugin is set to “ API key” mode. * What is sent and when: every time WordPress sends an email (`wp_mail()`), the plugin sends the recipients, sender address and name, Reply-To, subject, message body, attachments and custom `X-` headers of that email, together with your API key. The request also carries the plugin and WordPress version in the User-Agent; the address of your site is not added. **2. SMTP Senpai account status** – `https://app.mailsenpai.com/relay/v1/stato` * What it is for: checking that the API key is valid and showing the account status box (volume, usage, SMTP details). * What is sent and when: your API key, when you save a new key, when you open the plugin Dashboard or Settings page (the answer is cached for ten minutes) and when you click “Refresh”. The admin bar item never calls the service: its status comes from the local email log. **3. SMTP relay** – `relay.mailsenpai.com` (or the host you enter) * What it is for: delivering the emails of your site when the plugin is set to “ SMTP” mode. * What is sent and when: every email sent by WordPress, with your SMTP username and password, over an encrypted connection (STARTTLS by default). **4. Email DNS check** – `https://app.mailsenpai.com/tools/dns-check` * What it is for: the “Sender domain check” tool. * What is sent and when: only the domain name you enter and the language of the answer (English or Italian), when you click “Check domain”. No key and no personal data are sent. The services are provided by MailSenpai: [Terms and Conditions](https://en.mailsenpai.com/tc/)· [Privacy Policy](https://en.mailsenpai.com/privacy-policy/). ## Screenshots [⌊Dashboard: connection state, monthly volume, sender domain check and latest emails, with the "What to do if…" answers.⌉⌊Dashboard: connection state, monthly volume, sender domain check and latest emails, with the "What to do if…" answers.⌉[ Dashboard: connection state, monthly volume, sender domain check and latest emails, with the “What to do if…” answers. [⌊Guided setup in three steps. Here the sender domain is not verified yet: the plugin explains why and links to the page of the customer area where to verify it.⌉⌊Guided setup in three steps. Here the sender domain is not verified yet: the plugin explains why and links to the page of the customer area where to verify it.⌉[ Guided setup in three steps. Here the sender domain is not verified yet: the plugin explains why and links to the page of the customer area where to verify it. [⌊Settings: API key or SMTP, sender, email log and admin bar options, with the account status on the side.⌉⌊Settings: API key or SMTP, sender, email log and admin bar options, with the account status on the side.⌉[ Settings: API key or SMTP, sender, email log and admin bar options, with the account status on the side. [⌊Test & domain check: send a test email and check SPF, DKIM, DMARC and MX of the sender domain, with what to fix.⌉⌊Test & domain check: send a test email and check SPF, DKIM, DMARC and MX of the sender domain, with what to fix.⌉[ Test & domain check: send a test email and check SPF, DKIM, DMARC and MX of the sender domain, with what to fix. [⌊Email log: date, status, method, recipients, subject and details of the latest emails, filtered by status.⌉⌊Email log: date, status, method, recipients, subject and details of the latest emails, filtered by status.⌉[ Email log: date, status, method, recipients, subject and details of the latest emails, filtered by status. [⌊Help: the common problems explained in plain words, with the link to fix each of them.⌉⌊Help: the common problems explained in plain words, with the link to fix each of them.⌉[ Help: the common problems explained in plain words, with the link to fix each of them. [⌊Admin bar item with the status symbol and quick links.⌉⌊Admin bar item with the status symbol and quick links.⌉[ Admin bar item with the status symbol and quick links. [⌊The Dashboard on a phone.⌉⌊The Dashboard on a phone.⌉[ The Dashboard on a phone. ## Installation 1. Install and activate the plugin from **Plugins Add New**, or upload the `smtp- senpai` folder to `/wp-content/plugins/`. 2. Open **SMTP Senpai** in the admin menu: the Dashboard guides you through the setup in three steps. 3. In **SMTP Senpai Settings** choose **API key (recommended)** and paste the key( it starts with `msp_`) from the SMTP Senpai page of your MailSenpai customer area. Or choose **SMTP** and enter the SMTP username and password. 4. Enter a sender address on a domain verified in your account and save. 5. Send a test email from the Dashboard or from **Test & domain check**, and check your domain. Optional: keep secrets out of the database by adding them to `wp-config.php`: ``` define( 'SMTPSENPAI_API_KEY', 'msp_...' ); define( 'SMTPSENPAI_SMTP_PASSWORD', '...' ); ``` ## FAQ ### Do I need an SMTP Senpai account? Yes. The plugin sends email through SMTP Senpai, so you need an account and an API key or SMTP credentials. Until the plugin is configured, WordPress keeps using its default mailer. ### Where do I find the API key? In the MailSenpai customer area, on the SMTP Senpai page. The key starts with `msp_`. See the [documentation](https://en.mailsenpai.com/smtp-api/). ### Which sender address can I use? An address on a domain verified in your SMTP Senpai account (subdomains are accepted). If WordPress or another plugin uses a different domain, the API answers with an error that the plugin shows in the log and in the test email result. ### How do Cc and Bcc work in API mode? The API sends every recipient (To, Cc and Bcc together, up to 50) an individual copy, so the Cc list is not shown to the other recipients. If you need visible Cc headers, use SMTP mode. ### What happens if the API is unreachable? The email fails and the error is written in the log. If you turn on the fallback option, the email is handed to the default WordPress mailer instead. Addresses on your suppression list are never retried. ### What does the log store? Date, status, sending method, recipients, subject, message ID and error text. Message bodies and attachments are never stored. Privacy mode masks the addresses (m***@ example.com) and drops the subjects. Entries are deleted automatically after 7, 14 or 30 days. ### Does it work on multisite? Yes. Activate it network-wide or per site: each site has its own settings, log and cleanup schedule. ### Does the plugin track me or my visitors? No. The plugin does not collect usage data, does not load external scripts, fonts or images and does not show ads. ### Can I hide the icon in the admin bar? Yes. Go to **SMTP Senpai Settings Display** and untick “Show in the admin bar”. The item is only shown to users who can manage the plugin. ### I had bookmarked Settings SMTP Senpai. Does the link still work? Yes. The old address opens the new pages of the SMTP Senpai menu. ### What is removed when I delete the plugin? All its options, cached data, scheduled events and the log table, on every site of a network. ## Reviews There are no reviews for this plugin. ## Contributors & Developers “SMTP Senpai” is open source software. The following people have contributed to this plugin. Contributors * [ MailSenpai ](https://profiles.wordpress.org/mailsenpai/) [Translate “SMTP Senpai” into your language.](https://translate.wordpress.org/projects/wp-plugins/smtp-senpai) ### Interested in development? [Browse the code](https://plugins.trac.wordpress.org/browser/smtp-senpai/), check out the [SVN repository](https://plugins.svn.wordpress.org/smtp-senpai/), or subscribe to the [development log](https://plugins.trac.wordpress.org/log/smtp-senpai/) by [RSS](https://plugins.trac.wordpress.org/log/smtp-senpai/?limit=100&mode=stop_on_copy&format=rss). ## Changelog #### 1.1.2 * Translations are now delivered by translate.wordpress.org: the bundled Italian files and the manual loading of the text domain were removed. #### 1.1.1 * Status shown with symbols instead of coloured dots: a check mark when it works, a clock while the setup is not finished or the account is being activated, a warning sign when there is a problem, a cross when the account is suspended. The status is always written next to the symbol. Applies to the page header, the dashboard, the email log, the domain check and the admin bar. * The email log labels the message ID in the Details column. * Italian translation updated. #### 1.1.0 * New SMTP Senpai menu with its own monk icon: Dashboard, Settings, Test & domain check, Email log, Help. The old Settings SMTP Senpai address redirects to the new pages. * New Dashboard: connection state, monthly volume bar, latest emails, sender domain check result. * Guided setup in three steps with progress, and a one-click test email to yourself. * Plain explanations and direct links for the common errors (sender domain not verified, DKIM not active yet, key not valid, account suspended or being activated, monthly volume used up, connection problems), in notices, in the log and on the new Help page. * Admin bar item with status dot (green, orange, red) and quick links; only for administrators, can be turned off (“Show in the admin bar”). * New design in the MailSenpai colours, responsive and accessible (focus states, labels for screen readers, contrast). Logo, icon and font are bundled with the plugin. * Italian translation updated. #### 1.0.0 * First release: API and SMTP sending, test email, sender domain check, account status, email log, Italian translation. ## Meta * Version **1.1.2** * Last updated **2 days ago** * Active installations **Fewer than 10** * WordPress version ** 5.7 or higher ** * Tested up to **7.1.3** * PHP version ** 7.4 or higher ** * Tags * [deliverability](https://wordpress.org/plugins/tags/deliverability/)[email](https://wordpress.org/plugins/tags/email/) [smtp](https://wordpress.org/plugins/tags/smtp/)[transactional email](https://wordpress.org/plugins/tags/transactional-email/) [wp-mail](https://wordpress.org/plugins/tags/wp-mail/) * [Advanced View](https://wordpress.org/plugins/smtp-senpai/advanced/) ## Ratings No reviews have been submitted yet. [Your review](https://wordpress.org/support/plugin/smtp-senpai/reviews/#new-post) [See all reviews](https://wordpress.org/support/plugin/smtp-senpai/reviews/) ## Contributors * [ MailSenpai ](https://profiles.wordpress.org/mailsenpai/) ## Support Got something to say? Need help? [View support forum](https://wordpress.org/support/plugin/smtp-senpai/)