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Does CSS ::first-letter Work in HTML Email?

Applies styles to the first letter of a block-level element.

Quick Answer

Does ::first-letter work in HTML email?

The CSS ::first-letter property is supported in Apple Mail, Yahoo! Mail, Samsung Email, Thunderbird, and others. It is NOT supported in Gmail, Outlook (Windows). Always include a safe fallback for unsupported clients.

Which Email Clients Support CSS ::first-letter?

CSS support for ::first-letter across email clients

Email ClientDesktopMobile / WebNotes
Gmail✗ No✗ No—
Outlook (Windows)✗ No?—
Outlook (Mac / Web)~ Partial✗ No—
Apple Mail✓ Yes✓ Yes—
Yahoo! Mail✓ Yes✓ Yes—
Samsung Email?✓ Yes—
Thunderbird✓ Yes?—
ProtonMail✗ No✓ Yes—
Fastmail✓ Yes?—

Notes

  • #1 Not supported with non Outlook accounts.
  • #2 Partial. Only supported on type selectors.

Frequently Asked Questions

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Paste your HTML and see how it renders in clients that don't support
::first-letter.

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Building a new email instead of checking an existing one? MailViewr's Email Builder only lets you use CSS that's known to render across clients, so ::first-letter can't sneak into your markup by accident. Open the Email Builder →