Email Subscriptions

Table of contents

  1. How it works
  2. Setup
  3. Broadcasts
  4. Email rendering
  5. Privacy and GDPR

How it works

Readers can subscribe to your blog by email. When you publish a post, it is automatically delivered to all subscribers, styled to match the web version.

Email delivery is handled by Resend. AgBlogger never stores subscriber email addresses — Resend keeps the contact list, sends the emails, and manages unsubscribes. Your server stores only the encrypted Resend API key and a history of sent broadcasts.

Subscribing uses double opt-in: a reader enters their address on the subscribe page, receives a confirmation email, and is added to the list only after clicking the confirmation link.

Setup

You need a Resend account (the free tier works for small blogs):

  1. Sign up at resend.com and verify your sending domain under Domains
  2. Create an API key with full access under API Keys

Then in AgBlogger:

  1. Open Admin → Subscriptions
  2. Paste the Resend API key
  3. Set the From email (an address on your verified domain) and optionally a From name
  4. Turn on Enable subscriptions and save

On first enable, AgBlogger automatically creates the contact list in Resend and — when your blog is served over HTTPS — registers an unsubscribe webhook so contacts who unsubscribe are permanently deleted from Resend.

If the webhook can’t be registered (for example, the blog isn’t reachable over HTTPS yet), subscriptions still work fully; the admin panel shows a warning that unsubscribed contacts won’t be auto-deleted from Resend, and registration is retried on later settings saves.

Once enabled, a Subscribe button appears in the blog header, linking to the public subscribe page.

To verify everything works, use Send test email in the admin panel to send yourself a sample broadcast.

Broadcasts

  • Automatic — publishing a post (creating it as published, or flipping a draft to published) sends it to all subscribers in the background. Each post is broadcast automatically at most once, so editing or republishing won’t email subscribers again.
  • Manual — pick any published post in Admin → Subscriptions and send it explicitly. Manual sends bypass the once-per-post guard, so double-check the broadcast history first to avoid emailing the same post twice.
  • History — the admin panel lists every broadcast attempt with its delivery status and any error, along with the current subscriber count.

Email rendering

Broadcast emails mirror the on-site post styling: headings, links, syntax-highlighted code blocks, blockquotes, note callouts, tables, and footnotes are restyled with email-safe inline CSS. Relative links and images are rewritten to absolute URLs, and footnote/anchor links point to the post on your blog. Each email includes a view-online link and an unsubscribe link.

Email clients can’t run the JavaScript used for math rendering on the web, so LaTeX formulas are embedded as images rendered by the external service latex.codecogs.com (with the raw TeX as alt text). Loading these images exposes the reader’s IP address to that service, like any remote image in email.

Privacy and GDPR

  • No subscriber data on your server — email addresses live only in Resend; AgBlogger stores none, and the subscribe endpoint never reveals whether an address is already subscribed.
  • Deletion on unsubscribe — with the webhook registered, unsubscribed contacts are permanently deleted from Resend.
  • Optional GDPR fields — controller name, contact, privacy policy URL, and postal address can be set in the admin panel.
  • Built-in privacy policy — if you haven’t created your own privacy page, AgBlogger serves a generated policy covering the subscription data processing, linked discreetly from the site footer while subscriptions are enabled.

Under GDPR, you remain the data controller and Resend acts as your data processor. Resend’s DPA is incorporated automatically when you accept their terms of service — review it if you have EU subscribers.