HTML Email Template Inconsistencies
All PoliteMail Builder templates are tested to minimize the impact of rendering inconsistencies across email clients. Rendering inconsistencies may still occur but should be limited to minor spacing or font differences; the general structured column layouts in a Template should remain the same.
That said, HTML email templates can behave inconsistently across different email clients and operating systems due to a variety of factors.
Rendering Engines
Different email clients and operating systems use different rendering engines to display HTML. For example, Outlook for Windows uses Microsoft Word’s rendering engine, whereas Outlook for Mac uses WebKit, the same rendering engine used by Safari. This can cause Outlook for Windows and Outlook for Mac to render the same email template slightly differently due to their distinct rendering engines.
NOTE: Email clients can apply updates to their rendering engines at any time. These updates may affect how HTML email templates are displayed.
Fonts
Email clients and operating systems might handle fonts differently. Generally, if you are using a unique or custom font, the font must also be installed on the recipient's device to be displayed correctly. If a unique font must be used, fallback fonts should be defined in the event the unique font is incompatible with the email client’s rendering engine on the receiving end. Some web fonts might not be supported in some clients.
For example, Calibri is a popular font, but it is not universally considered a web-safe font for email design. Calibri is a default font for Microsoft Office applications, but is not a pre-installed font on macOS, so it may not be available on Apple devices unless the user has specifically installed it.
It is recommended to use reliable web-safe fonts including the following:
- Times New Roman
- Georgia
- Arial
- Tahoma
- Trebuchet MS
- Courier New
- Lucida Console
By avoiding complex layouts and advanced CSS features, sticking to basic HTML, and using web-safe fonts for email design, you can maximize compatibility while reducing inconsistencies across email clients and devices.
