Below is some technical information about the email format and markup that DailyStory adds to your email.
Unsubscribe headers, List-Unsubscribe and List-Unsubscribe-Post, are automatically added to the header of all DailyStory emails. This is to conform with CAN-SPAM.
| Header | Description |
| List-Unsubscribe | An email header with a URL that takes the recipient to a location where they can unsubscribe from future emails. |
| List-Unsubscribe-Post | An instruction that email clients, such as Gmail, can send an HTTP POST to the URL listed in the List-Unsubscribe header to one-click unsubscribe a recipient. |
DailyStory includes the List-Unsubscribe and List-Unsubscribe-Post headers in the DKIM (DomainKeys Identified Mail) signature for every outbound email. This means these headers are cryptographically signed alongside the message body and other protected headers — any modification to them in transit will cause DKIM verification to fail at the receiving mail server.
Signing these headers matters for two reasons. First, it proves the unsubscribe mechanism was set by the verified sending domain and has not been tampered with. Second, Gmail, Yahoo Mail, and other major inbox providers require that List-Unsubscribe headers be DKIM-signed as part of their bulk sender requirements. Without a valid DKIM signature covering these headers, providers may decline to show the one-click unsubscribe prompt to recipients, which can negatively affect deliverability and complaint rates.
No additional configuration is required. As long as your sending domain has DKIM configured in DailyStory, unsubscribe headers are signed automatically on every email sent.
If the *|UNSUBSCRIBE|* merge tag is not found in the body of an email an unsubscribe link is automatically inserted at the end of the email.
DailyStory also sets the following email-level headers on every outbound message to suppress automated responses and signal to receiving mail systems that the message is bulk mail.
| Header | Value | Description |
| X-Auto-Response-Suppress | OOF, AutoReply | Instructs mail servers and clients (primarily Microsoft Exchange and Outlook) to suppress out-of-office replies and auto-replies to this message. This prevents reply loops when sending to large lists. |
| Precedence | bulk | A widely-recognized convention that signals the message is bulk mail. Many mail servers use this to suppress auto-replies and to apply appropriate filtering treatment. |
DailyStory will automatically set the DOCTYPE to instruct HTML parsers that the content in the email is XHTML 1.0 Transitional:
DailyStory automatically injects a standard set of meta tags into every email's <head>. These fall into four functional groups:
These tags control how email clients render and scale the message.
| Meta Tag | Value | Purpose |
| x-apple-disable-message-reformatting | (no value) | Prevents iOS Mail from automatically resizing or reflowing the email layout for mobile. Without this, Apple Mail may override your carefully crafted responsive design. |
| X-UA-Compatible | IE=edge | Tells Internet Explorer — and more importantly, Microsoft Outlook's rendering engine — to use the highest rendering mode available rather than falling back to a legacy compatibility mode. |
| viewport | width=device-width, initial-scale=1 | Ensures the email scales to match the device's screen width on mobile. Without this, many mobile clients render the email at a fixed desktop width and require the user to zoom in. |
Email clients and mobile operating systems will automatically detect patterns like phone numbers, addresses, and dates and turn them into tappable links — often changing their color, underline, or font weight in ways that break your design. These tags disable that behavior:
| Meta Tag | Value | Purpose |
| format-detection | address=no | Stops the email client from auto-linking physical addresses as map links. |
| format-detection | date=no | Stops the email client from auto-linking date strings as calendar events. |
| format-detection | telephone=no | Stops the email client from auto-linking phone numbers as dial links. |
These tags define the document type and character encoding. Both are set explicitly for maximum compatibility across email clients:
| Meta Tag | Value | Purpose |
| Content-Type | text/html; charset=utf-8 | Declares the document as HTML and specifies UTF-8 encoding, which supports the full range of characters including international text and emoji. |
| charset | UTF-8 | A standalone character set declaration repeated for older email clients that may not read the Content-Type attribute. |
Some ESPs expose a web-hosted version of each sent email. These tags prevent unintended indexing or referrer leakage if the email is viewed in a browser:
| Meta Tag | Value | Purpose |
| ROBOTS | NOINDEX, NOFOLLOW | Instructs search engine crawlers not to index the email content or follow any links within it if the email is rendered as a web page. |
| referrer | no-referrer | Prevents the browser from sending the email's URL as a Referer header when a recipient clicks a link inside the email, protecting the source URL from being exposed to third-party sites. |
VML & Office namespace declarations: DailyStory's email templates include XML namespace declarations (xmlns:v and xmlns:o) in the <html> tag. These are required for VML (Vector Markup Language), which Microsoft Outlook uses to render background images, rounded buttons, and other visual elements that CSS alone cannot reliably handle in Outlook's Word-based rendering engine.
Hidden preheader text: Immediately following the <body> tag, DailyStory inserts a hidden <div> containing the email's preheader — the preview text that appears after the subject line in a recipient's inbox. While not a meta tag, it serves the same purpose: providing metadata about the email's content before the recipient opens it. The preheader text can be customized in the Email Designer.