MailBolt SMTP Pro is an add-on for the free MailBolt SMTP plugin. It adds API mailers, an email log, a backup connection, smart routing, failure alerts, a weekly summary, WordPress notification controls and stats. The basics (Other SMTP, presets, From settings, test email, wizard, encryption, wp-config constants) are covered in MailBolt > Documentation.
mailbolt-smtp-pro-1.0.1.zip, click Install Now, then Activate. If the free plugin is missing, Pro shows a notice and does nothing.{prefix}mailbolt_log and two WP-Cron events: a daily log clean-up and a weekly summary (Mondays).Your site needs outgoing HTTPS (WordPress HTTP API) for API mailers and webhooks, and working WP-Cron for the weekly summary and log clean-up.
| Mailer | Fields | Notes |
|---|---|---|
| SendGrid | API key | Key needs "Mail Send" permission; verify your sender or domain. |
| Mailgun | Private API key, Sending domain, Region (US/EU) | Sent through the messages.mime endpoint. |
| Brevo | API key (v3) | Sender must be verified in Brevo. |
| Postmark | Server API token, Message stream | Stream is usually outbound. |
| Amazon SES | Access key ID, Secret access key, Region | SES API v2 with Signature V4. The IAM user needs ses:SendRawEmail (and ses:SendEmail); verify the From address/domain in that region and leave the SES sandbox for unrestricted sending. |
| SMTP2GO | API key | Verify your sender domain. |
| Resend | API key | Verify your domain in Resend. |
| Gmail / Google Workspace | Client ID, Client secret, Connect | See section 3. |
| Microsoft 365 / Outlook | Client ID, Client secret, Tenant, Connect | See section 3. |
Keys are encrypted like the SMTP password and never shown again; leave a field blank to keep the saved key. Provider errors appear in the test result, Tools > Last 20 errors, and the log.
You use your own app, so there are no shared limits and nothing passes through 007AJ.
Gmail / Google Workspace
/wp-admin/admin-post.php address).gmail.send.Microsoft 365 / Outlook
common, or your tenant ID) into MailBolt, choose the Microsoft card, save, click Connect.Access tokens are refreshed on the server automatically and stored encrypted. Disconnect removes the stored token.
Under Settings > Backup connection choose a second mailer (it must be configured too). If the main mailer fails, MailBolt retries that email once through the backup. The log shows the failed attempt and the backup send marked "(backup)". The backup cannot be the same as the main mailer.
Up to 5 rules: If Recipient / From email / Subject contains some text, send with a mailer. Rules are checked top to bottom, the first match wins, matching ignores case, and Recipient checks To, Cc and Bcc. Emails with no match use the main mailer. Leave "contains" empty to disable a row. Example: Subject contains order → Amazon SES.
[redacted]: password-reset links (wp-login.php?action=rp / resetpass with key=), set-password tokens, WooCommerce/EDD download keys (key=, download_file=, eddfile=, token=), any token/key/code/otp URL parameter, and 4–8 digit one-time codes next to words like "code", "OTP" or "verification". Subjects are always redacted the same way. Developers can change the patterns with the mailbolt_log_redact_patterns filter (array of regex => replacement).[redacted], and attachments are not stored, so they are not resent. If no body was saved, the Resend button is disabled with an explanation, and bulk resend skips those entries and tells you.mailbolt_pro_daily, scheduled on activation and whenever settings are saved, removed on deactivation) deletes older entries in batches of 500.When an email fails, MailBolt notifies every configured channel, at most once per channel every 15 minutes:
{"text": ...}).{"content": ...}).{"text": ...}).event (email_failed), site, to, subject, error, mailer, time.Webhook URLs are stored encrypted. Send a test alert clears the throttle and sends a sample to every configured channel.
Tick Email a 7-day sent/failed summary every Monday and optionally enter a recipient (default: the site admin email). Counts come from the email log, so logging must be on. It relies on WP-Cron, which runs when your site gets visits (or a real cron job).
Untick any of: New user registered (to admin), New user welcome (to the user), Password changed, Email address changed, Comment awaiting moderation, New comment (to the post author), Automatic core / plugin / theme update results. Unticked emails are switched off using WordPress's own filters.
MailBolt > Stats shows sent and failed counts for each of the last 30 days (UTC) with simple bars, based on the email log.
Every Pro field can be defined as a constant named MAILBOLT_ plus the field key in capitals, which makes it read-only in the settings:
define( 'MAILBOLT_MAILER', 'sendgrid' ); define( 'MAILBOLT_SENDGRID_KEY', '...' ); define( 'MAILBOLT_MAILGUN_KEY', '...' ); define( 'MAILBOLT_MAILGUN_DOMAIN', 'mg.example.com' ); define( 'MAILBOLT_BREVO_KEY', '...' ); define( 'MAILBOLT_POSTMARK_TOKEN', '...' ); define( 'MAILBOLT_SES_ACCESS_KEY_ID', '...' ); define( 'MAILBOLT_SES_SECRET_KEY', '...' ); define( 'MAILBOLT_SES_REGION', 'us-east-1' ); define( 'MAILBOLT_SMTP2GO_KEY', '...' ); define( 'MAILBOLT_RESEND_KEY', '...' ); define( 'MAILBOLT_GMAIL_CLIENT_ID', '...' ); define( 'MAILBOLT_GMAIL_CLIENT_SECRET', '...' ); define( 'MAILBOLT_MS_CLIENT_ID', '...' ); define( 'MAILBOLT_MS_CLIENT_SECRET', '...' ); define( 'MAILBOLT_MS_TENANT', 'common' );
Deactivating Pro removes its cron events; the free plugin keeps working with Other SMTP or PHP mail. Deleting Pro with Settings > Uninstall > Delete all MailBolt settings ticked also drops the log table and removes Pro keys and tokens.
Pro connects only to the mailers and webhooks you configure. By default the log stores recipients, subject, status, date, mailer, attachment names and error only; bodies and headers are stored only if you turn on Save email body, and then with secrets redacted. Entries are deleted after 30 days by default. Nothing is sent to 007AJ.