Provider Adapters

Provider adapters send mail through an HTTP API instead of SMTP — usually faster, more reliable, and with richer delivery feedback. Each adapter lives in its own Go module under providers/ so the core library stays dependency-free. Every adapter implements the standard email.Sender interface, so you can swap providers, wrap them in middleware, or feed them to AsyncSender with no other code changes.

SendGrid

go get github.com/KARTIKrocks/goemail/providers/sendgrid

import (
    email "github.com/KARTIKrocks/goemail"
    "github.com/KARTIKrocks/goemail/providers/sendgrid"
)

sender, err := sendgrid.New(sendgrid.Config{
    APIKey: os.Getenv("SENDGRID_API_KEY"),
})
if err != nil {
    log.Fatal(err)
}

mailer := email.NewMailer(sender, "no-reply@example.com")

Mailgun

go get github.com/KARTIKrocks/goemail/providers/mailgun

import "github.com/KARTIKrocks/goemail/providers/mailgun"

sender, err := mailgun.New(mailgun.Config{
    Domain: "mg.example.com",
    APIKey: os.Getenv("MAILGUN_API_KEY"),
    // BaseURL: "https://api.eu.mailgun.net", // for EU accounts
})

AWS SES

The SES adapter uses the AWS SDK v2 SES v2 client. AWS credentials are picked up from the ambient environment (env vars, EC2 instance role, IAM role for service accounts, etc.).

go get github.com/KARTIKrocks/goemail/providers/ses

import "github.com/KARTIKrocks/goemail/providers/ses"

sender, err := ses.New(context.Background(), ses.Config{
    Region: "us-east-1",
})

OpenTelemetry

otelmail is a middleware, not a sender — it adds a distributed-tracing span around every send. Each span carries email.from, email.to, email.subject, and email.recipients.count attributes; failures record the error and set status to Error.

go get github.com/KARTIKrocks/goemail/providers/otelmail

import (
    email "github.com/KARTIKrocks/goemail"
    "github.com/KARTIKrocks/goemail/providers/otelmail"
)

wrapped := email.Chain(sender,
    otelmail.WithTracing(),       // creates a span per Send
    email.WithLogging(logger),
)

// Optional: customize the tracer or span name
// otelmail.WithTracing(otelmail.WithTracerName("myapp.email"))