Lotus Notes (now IBM Notes) is an enterprise productivity solution that provides, as one of its many features, an email client. While Notes refers to the client application, it is typically combined with the Domino server and sold as a package.
Aside from Microsoft Outlook, Lotus Notes is one of the most hated email clients when it comes to designing HTML emails. Early versions of Lotus Notes had virtually no support for common HTML and CSS best practices and, while newer versions have improved a bit, emails generally rendered poorly in the client.
Fortunately for marketers, Lotus Notes a very small market share. In the past year, Lotus Notes never rose above 0.53% of total opens. Even looking at just desktop opens, the highest Lotus Notes ever achieved was 1.68% of opens. If you are doing B2C marketing, Lotus Notes is essentially a ghost—stop worrying about it.
However, many large corporations still rely on the Notes/Domino platform. As of 2008, IBM claimed that nearly 145 million licenses had been sold. B2B marketers will still need to take Notes into account, but shouldn’t live-and-die by its rendering engine—most businesses have moved to more popular services like Microsoft’s Exchange server or Google Apps.
Both Lotus Notes and the Domino server were built to be extended by third-party solutions. As such, a number of filters exist as add-ons to the core Domino server. These filters can have a wide variety of deliverability rules in place, making deliverability for Lotus Notes difficult to document. Adhering to email design best practices and CAN-SPAM rules is the best way to ensure deliverability.
Lotus Notes is a huge source of frustration for email designers, typically due to the lack of support for HTML and CSS.
With earlier versions of Notes (6 & 7), it’s easier to describe what is supported rather than what is not. When it comes to manipulating text, Notes 6/7 allows you to control font-family, -style, -size, and -weight, as well as text-align and -decoration. You can also manipulate the color of text using the color property.
Unfortunately, that is about all. Notes 6/7 supports the display property, but pretty much everything else, in terms of the box-model and positioning, is off- limits, including designer favorites like padding, max-width, and background-color.
Designers should note that both Notes 6 and 7 do not support the PNG image format. Emails that rely on PNGs (usually for their transparency) will encounter emails rendering similar to when images are disabled by default.
With Lotus Notes 8, IBM greatly improved the rendering of HTML emails. Most text formatting properties are supported, with the main exceptions being CSS3 properties like text-fill-color, text-fill-stroke, and text-shadow.
While support for the background shorthand is still missing, with Notes 8+, designers can use the background-color property. Box-model support has been improved, with support for height, width, margin, and padding being added in Notes 8. Designers can also rely on most positioning properties to work, with the exceptions being things like outline, overflow, opacity, visibility, and z-index, all rarely used by email designers.
Similar to most desktop clients (with Apple Mail being the exception), all versions of Lotus Notes lacks support for modern HTML5 and CSS3.
Lotus Notes 8.5 will ignore styles that are grouped with properties that use vendor prefixes. Only use un-prefixed properties. For instance, border-radius can be safely used without vendor prefixes now. Lotus Notes 8.5 will not use it anyway.
One final note: Campaign Monitor did some research regarding nesting tables and found that Notes 6/7 does not support tables nested more than 8 deep. Designers may want to keep this in mind if they have a large number of early Notes users. Thankfully, that means very few of us need to worry about the issue.
IBM Notes Wikipedia
Campaign Monitor's Guide to CSS Support
Nested Tables in Email
Lotus Notes Doesn't Support PNG Images
Litmus Help: Notes Rendering
Lotus Notes Rendering Tips
WTF Corporate America, Standards Much?
I Hate Lotus Notes