Lynbro SMTP Mailer
| 开发者 | lynbro |
|---|---|
| 更新时间 | 2026年11月13日 17:22 |
| PHP版本: | 7.4 及以上 |
| WordPress版本: | 7.1 |
| 版权: | GPL-2.0-or-later |
| 版权网址: | 版权信息 |
详情介绍:
mail(), which Gmail, Outlook and most
inboxes treat as suspicious. Password resets, WooCommerce orders and contact-form
messages end up in spam, or never arrive at all.
Lynbro SMTP sends every WordPress email through a real, authenticated SMTP
server — your host's, your mailbox's, or a sending service such as Brevo, SendGrid,
Mailgun, Amazon SES or Postmark. And when something goes wrong, you find out, and
the email is not lost.
Everything is in this free plugin. There is no Pro version, no nag screens, no
"upgrade" buttons, no weekly emails from us and no other plugins installed behind
your back.
Why another SMTP plugin?
The well-known SMTP plugins either sell the email log, resend, backup connection and alerts as a paid
add-on, or give them away with a large interface built around API mailers and OAuth apps. Lynbro SMTP
Mailer does one thing — plain, authenticated SMTP — and adds what those leave out:
- Private by default: the log keeps message content only for failed emails, so password-reset links of a working site never sit in your database (one SMTP plugin's log was readable without login in 2025, CVE-2025-11833).
- Backup inside the same send: the visitor's form gets "sent", not an error, while the main server is down.
- Staging modes: redirect every email to one address with Cc and Bcc removed, or send nothing and only log — safe copies of a live shop.
- Plain-language diagnostics: the SMTP conversation with the password hidden, advice for the usual errors, a port check from your server and a local SPF/DMARC check (no external API).
- Hosts people actually use in Denmark and the EU: presets for Simply.com, one.com, IONOS, Brevo, Mailgun EU, Zoho EU next to the global ones.
- Any SMTP server — presets for Gmail / Google Workspace, Outlook / Microsoft 365, Brevo, SendGrid, Mailgun, Amazon SES, Postmark, Zoho, Mailjet, SMTP2GO, Simply.com, one.com and IONOS, each with a one-line hint on what the username and password are.
- Email log — every email with recipients (including Cc and Bcc), subject, status, the connection that sent it and the exact error. Search, filter by status, export to CSV.
- Resend — failed emails keep their content, so one click sends them again.
- Backup connection — when the main server fails, the same email goes out at once through a second SMTP server or PHP
mail(), in the same request. The visitor never sees an error. - Failure alerts — an email (sent with PHP
mail(), because your SMTP server may be what is down) and/or a webhook (Slack and Discord incoming webhooks, or your own endpoint: JSON withtextandcontent). At most one per hour. - Test & diagnostics — a test email with the full SMTP conversation (password hidden) and plain-language advice for the usual errors; a check of outgoing ports 587, 465, 25 and 2525; the SPF and DMARC records of your sender domain.
- Staging modes — send everything to one address (Cc and Bcc dropped, so real customers never get a copy), or send nothing at all and only log.
- Sender control — force the From address (and, separately, the From name), set a default Reply-To that is used only when an email has none, and send bounces to the From address.
- Credentials in wp-config.php — define
LYNBRO_SMTP_HOST,LYNBRO_SMTP_USER,LYNBRO_SMTP_PASSand friends to keep the login out of the database. Otherwise the password is encrypted with your site's keys. - Import host, port and sender from WP Mail SMTP, FluentSMTP, Easy WP SMTP or Post SMTP in one click.
- WP-CLI —
wp lynbro-smtp test,log,resend,purge,status. - Site Health test and a small Dashboard widget with the last seven days.
- The log keeps message content only for failed emails (so they can be resent), unless you choose otherwise. Password-reset links of a working site therefore never sit in the log.
- Entries are deleted after 30 days (you choose 1–365).
- The log is visible only to administrators; every action checks permissions and a security token. There is no public endpoint.
- Log entries are part of Tools → Export / Erase Personal Data.
- The plugin contacts no Lynbro service and collects no statistics.
安装:
- Install from Plugins → Add New (search for "Lynbro SMTP Mailer") or upload the ZIP, then activate.
- Open Lynbro → SMTP.
- Pick your provider, enter the username and password, set the From email, and save.
- Open Test & diagnostics and send a test email.
屏幕截图:
常见问题:
Which SMTP provider should I use?
Your host's mail server or your own mailbox works for small sites. For shops and anything with more than a few dozen emails a day, a sending service (Brevo, Mailgun EU, Amazon SES, Postmark, SendGrid) delivers better. All of them work with plain SMTP.
Gmail or Microsoft 365 says the password is wrong
Both need an app password, not your normal password, when two-step sign-in is on. Microsoft 365 also needs "Authenticated SMTP" enabled for the mailbox, and Microsoft is retiring password sign-in for SMTP — if it is switched off for your tenant, use a sending service instead. The Test tab tells you which of these it is.
Does Lynbro SMTP support Gmail or Microsoft OAuth ("Sign in with Google")?
No. OAuth needs an app verified by Google or Microsoft, which is the most common source of breakage in other SMTP plugins. App passwords and SMTP relays do the same job without it.
Is my SMTP password safe?
It is encrypted with libsodium using your site's secret keys, never shown again,
never written to the log and left out of the settings export. For the strongest
setup, define it as LYNBRO_SMTP_PASS in wp-config.php — then it is not in the
database at all.
What happens when my SMTP server is down?
With a backup connection set, the email goes through the backup in the same request. Without one, it is logged as failed with its content kept, an alert goes out if you set one up, and you can resend it from the log when the server is back.
My host blocks port 587 / 465
Run Check ports on the Test tab. Many sending services also listen on 2525. Otherwise ask your host to open the port.
Can I use it on a staging copy without emailing real customers?
Yes. Choose Test mode to send every email to your own address (Cc and Bcc are removed), or Do not send any email to only log them.
Does it work with WooCommerce and form plugins?
Yes. Lynbro SMTP works through wp_mail(), which WooCommerce, Contact Form 7,
WPForms, Gravity Forms, Fluent Forms and almost every other plugin use. Plugins
with their own built-in SMTP client (some booking plugins) bypass wp_mail() and
need their own settings.
Another SMTP plugin is active — is that a problem?
Yes: two plugins configuring the same email fight over it. Lynbro SMTP lists the other mail plugins it finds; deactivate them after importing their settings.
Is there a paid version?
No, and there will not be one with locked features. Lynbro makes several free plugins; paid services, if any, live on our website and are never required.
更新日志:
- When the backup connection delivered an email but the failure alert could not be sent with PHP mail(), Site Health reported "Emails failed to send" with the alert's own error and the real cause, the main SMTP server, was lost. The real failure is kept; Site Health now says separately that alerts by email do not get out on this server and suggests the webhook.
- Readme: External Services now names the one WordPress.org request the shared "Our plugins" screen makes — what is sent, when, and the WordPress.org terms and privacy policy.
- The plugin names and descriptions on "Our plugins" and in the suggestions are translatable.
- Links on Lynbro screens use the darker brand green, which meets WCAG AA contrast on the admin background.
- Shared Lynbro admin 1.1.0: after two weeks of use and a first success (for example settings saved), this plugin's own screen asks once, politely and without stars, whether it is doing its job. Answers are per user: "Maybe later" or "Don't ask again", and only one Lynbro plugin asks in any 30 days.
- A small "Suggested for this site" block under the plugin's main screen lists Lynbro plugins that fit what the site already uses (WooCommerce, forms, a Danish setup …), with the reason. It can be hidden; nothing installs on its own and nothing is sent anywhere.
- Tab labels on Lynbro screens meet WCAG AA contrast.
- Lynbro admin screens now read the plugin's bundled translations (languages/) when WordPress has no language pack for it, so a Danish admin sees Danish instead of English.
- New: email log in its own table — Cc, Bcc, Reply-To, status, connection and error; search, filter, paging, CSV export, bulk delete.
- New: resend failed emails from the log or with WP-CLI.
- New: backup connection (second SMTP server or PHP mail()) used inside the same send.
- New: failure alerts by email and webhook, Site Health test, Dashboard widget.
- New: Test & diagnostics tab — SMTP conversation with hidden credentials, error advice, port check, SPF/DMARC check.
- New: provider presets, wp-config.php constants, separate force-From name, default Reply-To, Return-Path.
- New: staging modes (redirect all email to one address, or do not send).
- New: import from WP Mail SMTP, FluentSMTP, Easy WP SMTP and Post SMTP.
- New: WP-CLI commands; personal data export and erasure.
- Fix: the settings page printed a piece of PHP code as text, and the Tools export did not know the plugin's settings.
- Privacy: message content is kept only for failed emails by default; passwords are left out of the settings export.
- Initial version: SMTP override, encrypted password storage, force-from, test send, rolling delivery log.