Overview | Emails Docs

Each provider has its own subpath, @effect-kit/emails/<name>, and provides the same Email service. The matrix shows what each one accepts. A message that uses a feature the provider lacks fails with UnsupportedFeatureError before any request.

Provider	Text	HTML	Both	Sender name	Cc	Bcc	Reply-to	Headers	Attachments	Inline images	Idempotency
Resend	yes	yes	yes	yes	yes	yes	multiple	yes	yes	yes	replay, 24 hours
Amazon SES	yes	yes	yes	yes	yes	yes	multiple	yes	yes	yes	no
Postmark	yes	yes	yes	yes	yes	yes	multiple	yes	yes	yes	no
SendGrid	yes	yes	yes	yes	yes	yes	one	yes	yes	yes	no
Mailgun	yes	yes	yes	yes	yes	yes	multiple	yes	yes	no	no
SMTP (Nodemailer)	yes	yes	yes	yes	yes	yes	multiple	yes	yes	yes	no
Brevo	yes	yes	yes	yes	yes	yes	one	yes	no	no	reject, 30 minutes
MailerSend	yes	yes	yes	yes	yes	yes	one	yes	no	no	no
Mailtrap	yes	yes	yes	yes	yes	yes	one	yes	yes	yes	no
Mailchimp Transactional	yes	yes	yes	yes	yes	yes	multiple	yes	yes	no	no
Azure Communication Services	yes	yes	yes	no	yes	yes	multiple	yes	yes	yes	no
ZeptoMail	yes	yes	yes	yes	yes	yes	multiple	yes	yes	yes	no
Scaleway	yes	yes	yes	yes	yes	yes	multiple	yes	yes	no	no
Lettermint	yes	yes	yes	yes	yes	yes	multiple	yes	yes	yes	replay, 24 hours
Plunk	no	yes	no	yes	no	no	none	no	no	no	no
eusend	yes	yes	yes	yes	yes	yes	multiple	yes	yes	yes	replay

Pick by the features your messages need: attachments and inline images, how many reply-to addresses, a sender name, and whether you need an idempotency key. Only Resend, Lettermint, eusend and Brevo support idempotency keys.

Plunk is HTML only with one recipient, and Azure takes no sender name. Read the same flags at runtime from email.capabilities, described in Capabilities.