Microsoft’s announcement regarding the discontinuation of support for SVG images directly inserted in the code of emails for Outlook Web and Outlook Windows marks a significant shift in email design. Although this change affects only a minority of creators, it highlights the technological choices to be prioritized to ensure the security and readability of electronic messages. Understanding the technical implications of this decision invites a rethinking of current and future email design standards.
What is an inline SVG image?
SVG images (Scalable Vector Graphics) differ from traditional formats like PNG or JPG due to their XML-based structure. Unlike raster images that store pixels, SVG encodes shapes, colors, and paths as mathematical and textual instructions. This specificity allows for resizing without quality loss, making the format appreciated for logos, icons, or adaptive graphic elements.
Embedding an SVG image inline involves placing its code directly within the HTML file when creating an email or a website. This practice offers advanced customization, allows dynamic modifications via CSS or JavaScript, and reduces dependence on external resources.
Why is Microsoft stopping support?
Behind this technical decision lies a major concern: computer security. Even though the use of inline SVG remains marginal in emails, the flexibility offered by this format can be exploited. An SVG file, though graphically appearing, can contain scripts or active data capable of executing malicious actions upon display in the mail client.
In the digital ecosystem, every feature that could be exploited represents a potential risk. Recent attacks have shown that some malicious actors can exploit the dynamic content allowed by SVG. As a precaution, Microsoft is disabling client-side native SVG image support, thus protecting its users against potential undesirable scenarios.
Is the BIMI standard affected?
Logos certified according to the BIMI standard (Brand Indicators for Message Identification) also use a lighter variant of the SVG format, but with very strict restrictions. These files undergo rigorous checks to neutralize any interactive or potentially dangerous elements. Additionally, when they are displayed, they appear outside the main body of the message and are not embedded in the content sent itself.
Thus, even though SVG remains the technical container, the “tiny-ps” version used by BIMI differs radically from the traditional SVGs embedded in promotional or transactional emails. The fact that Microsoft does not support this deployment does not impact the current situation related to the security or overall rendering of ordinary emails.
Safe alternatives for graphics in emails
In response to the removal of inline SVG support, email professionals are turning to other formats recognized for their universal compatibility. PNG and JPG images, and in some cases, GIFs, continue to ensure stable display regardless of the mail client used.
The integration of these files relies on links to servers hosting the resources, eliminating any capability of executing malicious scripts. This approach better aligns with the security requirements imposed in the mass distribution of emails, even if it sometimes involves a slight increase in the weight of the transmitted files.
What impacts for designers and businesses?
Although few designers used inline SVG in their templates, those affected now notice blank spaces where vector icons or illustrations once appeared. Quickly adapting methods becomes necessary to maintain the visual coherence of communications.
To avoid any visual disruption during the withdrawal of support, replacing embedded SVGs with optimized PNG or JPG versions ensures a smooth transition. Most tools specializing in email design today offer customized export modules, thus limiting additional work.
Comparison of commonly used formats in email
| Format | Email compatibility | Average weight | Resizeable without loss | Security risk |
|---|---|---|---|---|
| Inline SVG | Limited | Low | Yes | Vulnerable |
| PNG | Excellent | Medium | No | Low |
| JPG | Excellent | Low to medium | No | Low |
| GIF | Good | Variable | No | Low |
- PNG: preferred for transparency and detail sharpness
- JPG: ideal for photos or complex images thanks to its high compression rate
- GIF: used for light animations or simple illustrative elements
Towards a permanent evolution of email design
This decision made by Microsoft serves as a reminder that security always takes precedence over graphical innovations in the realm of email. It prompts regular reviews of tools and formats to anticipate adjustments imposed by major publishers.
The evolution also underscores the importance of finding a balance between creativity and regulatory compliance, questioning the place of personalization versus message robustness and user experience. Observing these changes allows one to adapt practices and stay relevant in a constantly evolving technical environment.
