How to Handle Resubscribe Requests with SendGrid

How to Handle Resubscribe Requests with SendGrid

If you've integrated SendGrid into your .NET app, you're probably sending transactional emails, newsletters, or onboarding campaigns with ease. But what happens when a user unsubscribes—then wants back in?

Most devs assume resetting a flag in their database will do the trick. Unfortunately, it won’t.

Even if you mark a user as Unsubscribed = false in your database, SendGrid will still block emails until they’re removed from its suppression list.

This is where many developers get stuck—and where my consulting services can help you sidestep hours of frustration. I’ve already solved this in DevStack, so you don’t have to.

✅ The Problem

Once a user is added to SendGrid’s Global Suppression List, they won’t receive emails, even if:

  • You explicitly call the API to send them a message
  • You've marked them as subscribed again in your database

This is intentional behavior to respect user consent—but it also means you need to explicitly manage resubscriptions.

🔁 How to Resubscribe a User

You have three main options depending on your setup:

1. Use the SendGrid Suppression Management API

Call SendGrid’s API to remove the user from the global suppression list:

var client = new SendGridClient("YOUR_API_KEY");
var response = await client.RequestAsync(
    method: SendGridClient.Method.DELETE,
    urlPath: $"asm/suppressions/global/{email}"
);

✅ This is the cleanest method and can be done server-side via an authenticated endpoint or admin panel.

2. Do It Manually via the SendGrid Dashboard

If you prefer a manual approach:

1. Log into SendGrid

2. Navigate to Suppressions → Global Unsubscribes

3. Search for the user’s email

4. Click Remove

This is useful for internal testing or one-off cases.

3. Build a Self-Service Resubscribe Page (Recommended)

Here’s how I handle this in DevStack:

  • Create a page at /resubscribe
  • Confirm user intent (e.g., via an opt-in checkbox or email confirmation)
  • Call the suppression API as shown above
  • Update your own DB to mark them subscribed again

This is the most scalable and user-friendly approach.

🛑 Common Mistake

Don’t just reset your Unsubscribe flag in the database.

That’s not enough. SendGrid still suppresses their email behind the scenes. You must clear the suppression from both:

LocationWhy It Matters
Your own DBAvoid sending to people who opted out
SendGrid suppression listActually allow mail delivery again

📝 UX Best Practice

Before resubscribing anyone, always get explicit opt-in confirmation. Use clear messaging like:

You previously unsubscribed. If you’d like to start receiving emails again, confirm below.

This protects both you and the user.

✅ Already Solved in DevStack

If you're building your email system from scratch, this could cost you hours of trial and error.

But in DevStack, I’ve already solved it. My built-in user management module:

  • ✅ Tracks email consent status server-side
  • ✅ Integrates directly with SendGrid’s API
  • ✅ Provides a ready-to-use /resubscribe page
  • ✅ Includes admin tools for managing user consent

Need help implementing this? See my CV or learn more about my business-led consulting services.

🧩 Related: What Else Comes with DevStack?

🔹 Automated email flows (welcome, recovery, engagement)

🔹 Full unsubscribe/resubscribe tracking

🔹 Targeted mailshots with GDPR-safe filters

🔹 Markdown + custom markup editor for email bodies

🔹 Shared codebase ready to deploy in .NET 8

Check my pricing or reach out via contact if you're ready to elevate your email strategy—and more.

email management