When viewing forwarded emails in Apple Mail on iPhone 13 mini or iPad, some emails (e.g., newsletters with background colors) display a white border on the right side of the email content. This issue does not occur consistently with all forwarded emails.

The screenshots show the Zalando newsletter (first confirmation email) received directly vs. via Addy.io, highlighting the difference. The issue seems specific to iOS, as it occurs on iPhone 13 mini and iPad but not in Apple Mail on macOS.

Possible Cause

The issue may be related to:
• max-width: 896px, padding: 10px 20px, and width: 100%.
• Lack of box-sizing: border-box;.

Affected Code

The relevant code is located in:
resources/views/emails/forward/html_banner.blade.php

Sreenshots

Forwarded via Addy.io

Regular email without Addy