go-notification

SendGrid (Twilio SendGrid) is a mature, enterprise-grade email platform with strong compliance story (SOC 2, GDPR, HIPAA BAA available on higher tiers).

Pricing

Free — 100 emails/day, forever.
Essentials — from $19.95/month for 50k emails.
Pro — from $89.95/month with dedicated IP, sub-user management.

Verify current pricing at https://sendgrid.com/pricing — tiers and limits change.

Setup

Create an account at https://sendgrid.com.
Complete sender authentication — either a single sender verification or full domain auth (SPF/DKIM/DMARC).
Create an API key with at least Mail Send permission.

main.go

import "github.com/gopackx/go-notification/channel/mail/sendgrid"

notifier.RegisterChannel("mail", sendgrid.New(sendgrid.Config{
    APIKey: os.Getenv("SENDGRID_API_KEY"),
    From:   "noreply@example.com",
    FromName: "My App",
}))

Configuration reference

Field	Type	Required	Description
`APIKey`	`string`	yes	SendGrid API key. Starts with `SG.`.
`From`	`string`	yes	Verified sender address.
`FromName`	`string`	no	Display name.
`ReplyTo`	`string`	no	Optional Reply-To header.
`Timeout`	`time.Duration`	no	HTTP timeout per send. Default: `30s`.

Sending

main.go

func (n OrderShipped) ToMail(u notification.Notifiable) *mail.Message {
    return mail.NewMessage().
        Subject("Your order shipped").
        Line("Tracking inside.").
        Action("Track", "https://example.com/track")
}

Troubleshooting

401 Unauthorized — bad API key, or the key is missing Mail Send scope.
403 Forbidden: The from address does not match a verified Sender — complete sender authentication in the SendGrid dashboard.
Emails in spam even on authenticated domain — check SendGrid's Stats → Engagement panel; high bounce or spam-complaint rates will downrank your IP reputation.