GlobalDev SMTP

GlobalDev SMTP connects WordPress wp_mail() to the provider you select.

All 18 mailer options are available in this free version:

• Default WordPress mail transport

• SendLayer (REST API)

• SMTP.com (HTTP API with channel and API key, or existing SMTP credentials)

• Brevo / Sendinblue (REST API, recipient-name fix)

• Amazon SES (SES v2 HTTPS API, AWS Signature Version 4)

• Google / Gmail (OAuth 2.0 and Gmail send API)

• Mailgun (US or EU HTTP API, MIME uploads)

• Microsoft 365 / Outlook (OAuth 2.0 and Microsoft Graph sendMail)

• Postmark (email API)

• SendGrid (Mail Send API)

• SparkPost (Transmissions API, US or EU)

• Zoho Mail (regional OAuth 2.0 and Mail API)

• Other SMTP (standard username/password authentication)

• toSend (v2 transactional email API)

• Netcore / Pepipost (current v6 Email API)

• Elastic Email (v4 Transactional API)

• SMTP2GO (v3 standard email API)

• Cloudflare Email Sending (account-scoped REST API)

Also includes a visual, context-aware setup guide for all 18 mailers (including exact field mappings and a copyable OAuth callback URL), sender identity settings, test sending, optional email metadata logging and timed cleanup, SPF/DMARC/MX presence checks, and detection of known SMTP-plugin conflicts.

IMPORTANT: Before using any mailer, the site administrator must configure credentials, sender authorization and the provider account. Real-world delivery depends on that service. All provider integrations should be tested in the site’s own environment, particularly OAuth flows and attachments.

This plugin does not operate a hosted GlobalDev email relay. Gmail OAuth apps may require Google verification, and Microsoft and Zoho require provider-specific application registration and permissions.

Technical limitations: Only one active mailer is configured at a time; no multiple connections or failover. HTTP providers currently map basic wp_mail() HTML/plain messages, To/Cc/Bcc/Reply-To and local attachments (some provider-specific limits apply). Arbitrary custom headers, recurring iCal/MIME edge cases, and delivery/bounce tracking are not fully supported on every HTTP provider.

Inline-image support differs by provider. The Default WordPress mailer does not override or log core PHP mail(). com supports dedicated API credentials or authenticated SMTP.

SparkPost uses structured messages for Cc/Bcc privacy.

Privacy and data use

No GlobalDev-hosted telemetry, advertising, analytics, or usage tracking is sent by this plugin. The plugin bundles its administrator graphics and scripts locally. Selecting a provider and enabling it causes WordPress email generated by the site (including messages triggered automatically by the site or installed plugins) to be forwarded to that configured provider.

The site administrator must decide if the chosen provider is appropriate, disclose sending in the site’s own privacy policy, and obtain any consent required by law.

On sending, the configured email service receives the From/Reply-To addresses and names, recipients (To, Cc, Bcc), subject, plain text and/or HTML body, and any local email attachments included by the calling plugin. Message headers and embedded images are included where supported by the transport. APIs receive authentication tokens/API keys in request headers; SMTP servers receive SMTP credentials when authentication is configured.

The provider and the site’s infrastructure may log network information such as the server IP address. The message data is transmitted when WordPress calls wp_mail() while that provider is enabled, and when the administrator sends a test message. Sending uses HTTPS for API mailers; SMTP transport security is configured by the administrator.

OAuth providers (Google, Microsoft, Zoho) also receive the authorization request and OAuth client information when an administrator clicks Connect, and token requests when connecting or refreshing credentials. OAuth callback requests return to the WordPress site. DNS diagnostics query DNS records for the configured sender domain using the site’s DNS resolver; they do not send message content to GlobalDev.

Optional local mail logging is disabled by default. When enabled it records timestamps, recipients, email subjects, acceptance/failure status, and a sanitized error message in a WordPress database table. It does not intentionally save message bodies or attachments.

Administrators can clear logs and configure retention. Credentials are encrypted at rest using site-specific WordPress secrets and OpenSSL. Local plugin records are removed on uninstall.

Third-party providers may retain their own copies independently; refer to their policies below.

External services

GlobalDev SMTP connects only to the selected service for actual email sending; it does not connect to all services listed below merely because the plugin is installed. The information sent is described in the Privacy and data use section above. Provider accounts and charges, server-side processing and retention are governed by the third party’s terms.

Links can change over time; check the policy applicable to your account.

• SendLayer (https://sendlayer.com/): transactional email delivery using its sending API. Connects when SendLayer is selected and email is sent. Terms: https://sendlayer.com/terms-of-service/; Privacy: https://sendlayer.com/privacy-policy/

• SMTP.com (https://www.smtp.com/): email delivery using configured SMTP.com API or SMTP credentials. Connects only when SMTP.com is selected and email is sent. Terms (provider policy link; confirm current URL): https://www.smtp.com/policies/terms-and-conditions/; Privacy (provider policy link; confirm current URL): https://www.smtp.com/policies/privacy-policy/

• Brevo (Sendinblue) (https://www.brevo.com/): transactional email API delivery. Connects when selected and email is sent. Terms: https://www.brevo.com/legal/termsofuse/; Privacy: https://www.brevo.com/legal/privacypolicy/

• Amazon SES / AWS (https://aws.amazon.com/ses/): AWS SES v2 delivery through a selected AWS region; uses AWS access-key credentials to sign email API requests. Connects when selected and email is sent. Terms: https://aws.amazon.com/service-terms/; Privacy: https://aws.amazon.com/privacy/

• Google / Gmail (https://developers.google.com/workspace/gmail/api): OAuth authorization and Gmail API sending. Connects to Google during OAuth and token renewal, and to Gmail when selected and sending. API Terms: https://developers.google.com/terms/; Privacy: https://policies.google.com/privacy; User data policy: https://developers.google.com/terms/api-services-user-data-policy

• Mailgun (https://www.mailgun.com/): sends emails to the configured US/EU Mailgun email API. Connects when selected and email is sent. Terms: https://www.mailgun.com/legal/terms/; Privacy: https://www.mailgun.com/legal/privacy-policy/

• Microsoft 365 / Outlook (https://learn.microsoft.com/en-us/graph/api/user-sendmail): Microsoft OAuth authentication and Microsoft Graph email sending. Connects to Microsoft identity services when authorizing/refreshing; to Graph when selected and sending. Terms: https://www.microsoft.com/servicesagreement; Privacy: https://privacy.microsoft.com/privacystatement

• Postmark (https://postmarkapp.com/): Postmark transactional message API. Connects when selected and sending. Terms: https://postmarkapp.com/terms-of-service; Privacy: https://postmarkapp.com/privacy-policy

• Twilio SendGrid (https://sendgrid.com/): SendGrid Mail Send API. Connects when selected and sending. Terms: https://www.twilio.com/en-us/legal/tos; Privacy: https://www.twilio.com/en-us/legal/privacy

• SparkPost (https://www.sparkpost.com/): SparkPost transmissions API, with US/EU region choices; service now associated with Bird. Connects when selected and sending. Terms: https://bird.com/legal/terms; Privacy: https://bird.com/legal/privacy; SparkPost historical privacy document: https://bird.com/legal/sparkpost-privacy-policy-v1

• Zoho Mail (https://www.zoho.com/mail/): Zoho OAuth authorization, token renewal and Zoho Mail API sending. Connects when selected. Zoho Mail’s current usage policy restricts automated/transactional mail; do not use this option for prohibited purposes. Consult the provider for an authorized sending product. Terms: https://www.zoho.com/terms.html; Privacy: https://www.zoho.com/privacy.html; Zoho Mail Usage Policy: https://www.zoho.com/mail/help/usage-policy.html

• toSend (https://tosend.com/): transactional email delivery API. Connects when selected and sending. Terms: https://tosend.com/legal/terms-of-service/; Privacy: https://tosend.com/legal/privacy-policy/

• Netcore Email API (Pepipost) (https://netcore.ai/): email delivery through Netcore regional email API. Connects when selected and sending. Terms: https://netcorecloud.com/terms-of-service/; Privacy: https://www.netcorecloud.com/privacy-policy/

• Elastic Email (https://elasticemail.com/): Elastic Email transactional API delivery. Connects when selected and sending. Terms: https://elasticemail.com/resources/terms/terms-of-use; Privacy: https://elasticemail.com/resources/usage-policies/privacy-policy

• SMTP2GO (https://www.smtp2go.com/): SMTP2GO API sending. Connects when selected and sending. Terms: https://www.smtp2go.com/terms/; Privacy: https://www.smtp2go.com/privacy/

• Cloudflare Email Sending (https://www.cloudflare.com/): Cloudflare account-scoped email API with an administrator-configured token and account ID. Connects when selected and sending. Terms: https://www.cloudflare.com/terms/; Privacy: https://www.cloudflare.com/privacypolicy/

• Other SMTP: sends via the SMTP hostname configured by the administrator; the terms and privacy policy are those of that chosen SMTP provider, not GlobalDev. Transport credentials and email content go to that server when sending.

• Default WordPress mail: uses the default WordPress/PHP mail transport; this plugin does not directly contact an external API for this option. Your hosting provider may route messages via its own SMTP infrastructure.

The plugin never uploads email bodies or recipient lists to GlobalDev servers. Before activating an external mailer, verify its availability, acceptable use, current policies, sender registration, data processing terms and regulatory requirements.