AuthenticSender

AuthenticSender replaces WordPress' default mail() function with configurable SMTP, UseSend API, or Resend API delivery, giving you control over how your site sends email. Delivery Method Choose SMTP (default), UseSend API, or Resend API. Existing SMTP configurations keep working unchanged when SMTP is selected. SMTP Configuration Enable or disable SMTP routing with a single checkbox. When disabled (and no API delivery method is selected), WordPress falls back to its default mail() function. Configure your server connection with:

• Host - your SMTP server hostname or IP address
• Port - any valid port (1-65535), defaulting to 25
• Encryption - None, TLS, or SSL
• Authentication - optional username and password (stored encrypted with AES-256-GCM)

Provider Presets Select a preset from the dropdown and the host, port, and encryption fields are filled in automatically. Supported providers:

• Gmail
• SendGrid
• Mailgun
• Postmark
• Hostinger
• UseSend (host smtp.usesend.com, username usesend, password = your API key)
• Resend (host smtp.resend.com, username resend, password = your API key)

For a self-hosted UseSend SMTP proxy, use Custom and enter your proxy host with the same username/API-key password pattern. UseSend API Send mail through the UseSend HTTP API instead of SMTP:

• Encrypted API key storage
• Cloud hosting (app.usesend.com) or self-hosted instance URL
• From, Reply-To, BCC, HTML/text, and attachments are mapped to the API

Resend API Send mail through the Resend HTTP API instead of SMTP:

• Encrypted API key storage
• Direct delivery through api.resend.com
• From, Reply-To, BCC, HTML/text, and attachments are mapped to the API

Sender Identity Override the From name and From email address on outgoing emails when SMTP is enabled or an API delivery method is selected. Enable Force Identity to apply From, Reply-To, and BCC even when using WordPress default mail. Additional Headers Set global Reply-To (email and name) and BCC addresses. These apply when SMTP is enabled, an API delivery method is selected, or when Force Identity is on. The BCC field accepts multiple comma-separated addresses. Password resets, email confirmations, and similar sensitive messages are never copied to BCC, so reset links and verification tokens are not shared with the BCC address. Test Email Send a test message directly from the settings page. AuthenticSender attempts delivery via wp_mail() and returns a clear success or error message, so a misconfiguration never leaves you guessing. Email Log Keep a database record of every email sent or failed. The log view includes:

• Timestamp, recipient, subject, status, and delivery method (SMTP, UseSend, Resend, or WP Default)
• Error message for failed deliveries
• Filter by All / Success / Failed
• Paginated table (20 entries per page)
• One-click Clear Log with confirmation prompt
• Configurable retention period (1-365 days); older entries are pruned automatically

Logging can be toggled on or off at any time from the Settings tab. Security

• SMTP passwords and API keys stored encrypted using AES-256-GCM with WordPress AUTH_KEY and SECURE_AUTH_KEY
• Unique (non-default, non-identical) authentication keys are required before new SMTP passwords or API keys can be saved; English and localized sample phrases are detected
• Self-hosted UseSend URLs must use HTTPS; localhost, private/reserved IPs, and unresolvable hosts are blocked by default; HTTP redirects are disabled
• Global BCC skips password resets, email confirmations, and similar sensitive mail by default
• Email log redacts subjects for the same sensitive-mail patterns
• Plugin settings (including credentials) are not autoloaded on front-end requests

1.0.2

• Add Resend SMTP provider preset.
• Add Resend HTTP API delivery with encrypted API-key storage.
• Log the delivery method as Resend when the API path is active.
• Separate shared API-mailer behavior from provider-specific UseSend and Resend logic.
• Honor earlier pre_wp_mail short-circuits and WordPress sender, content-type, and custom-header filters.
• Support display-name recipients, associative attachment filenames, and WordPress 6.9 embedded images for Resend.
• Preflight attachment limits, encode files in chunks, enforce provider count limits, and guard against unsafe memory use.
• Correct API-key field descriptions in the settings screen.

1.0.1

• Add UseSend SMTP provider preset.
• Add UseSend HTTP API delivery (cloud and self-hosted instance URL).
• Log the delivery method as UseSend when the API path is active.
• Warn when WordPress AUTH_KEY / SECURE_AUTH_KEY still use sample defaults.
• Require unique AUTH_KEY / SECURE_AUTH_KEY (including localized samples) before saving new credentials.
• Require HTTPS for self-hosted UseSend; block localhost/private IPs and unresolvable hosts by default; disable HTTP redirects.
• Reject invalid UseSend Instance URLs on save (keep previous value).
• Apply test-email rate limit when sending throws an exception.
• Redact sensitive email subjects in the email log.

1.0.0

• Initial release.