The RSVP Mailer tool included in RSVPMaker has undergone a significant overhaul, making it more useful for composing event invitations and email newsletters, which you can send either through your web server or through the integration with MailChimp.
The styling on this blog post is approximately what you would see in an email version of this same content.
Better integration with formatting in the WordPress block editor
For example, the text above is an H2 WordPress heading with the text color and background set in the editor, like this:

I can add simple layouts like a two-column presentation of information:
When to Use the Built-in Mailer
Sending to at most a few hundred people, such as everyone who registered for an event or all the users of your website. You can send different messages to just those who have or have not registered for an event.
When to use Mailchimp
Sending to hundreds or thousands of people through a high-capacity service with sophisticated handling of unsubscribes, spam filters, and bounced email.
You can still compose your messages in WordPress.
I can also include a YouTube video like this demo:
Among the advantages of composing messages in WordPress is that it’s easier to leverage WordPress content such as embedded posts or lists of posts, not to mention event invitations. MailPoet has some of the same advantages, but it uses its own WYSWIG editor rather than allowing you to use standard editor blocks. Also, I’ve had trouble using MailPoet on WordPress multisite installs.
RSVPMaker has had some version of these email capabilities for years, but significant improvements introduced this month include:
- Templates based on nested blocks, with an outer block you can style to set a background color for the body of your message and an inner block (with its own color options) that contains the body of your message. You can modify the template as I’ve done here to include the RSVPMaker banner up top or to change the default color scheme.
- Integration with your theme colors, particularly for newer themes that incorporate a theme.json file.
- Ability to add your own custom stylings. The inline styles system works by replacing an HTML class attribute with a set of CSS rules. Taking advantage of the Additional CSS class(es) option included with every WordPress block, you can specify inline CSS to be substituted when the content is sent by email. Or tweak the display of blocks added by other plugins.
- A Guest Email List Signup block you can use to sign people up for your list, in addition to the Add Me to Your Email List checkbox that can be included on RSVP forms. You can also add members to the email list manually or import a list downloaded from a service such as MailChimp.
- When sending to a list maintained on the web server, you can filter by RSVP status for an event. This is useful for membership organizations that want to be able to send a friendly reminder to members who have not yet registered and a different thank you / follow up message to those who have registered.
- YouTube videos embedded in an email are now represented with a bigger email preview image with a play button overlay.
Speaking of video, watch for a follow up email with a video demo as I work to document these features better. Meanwhile, I hope some of you will explore on your own and provide feedback.
Limitations
These formatting capabilities are based on inline CSS styles and don’t handle all the techniques you can use on a website. For example, the grid and row blocks aren’t supported. To approximate a columns effect, I can support two columns that each make up a little than half the width of the content area. At that size, a two-column layout is still readable when email is read on a phone rather than a PC. The responsive design techniques that allow regular WordPress columns to reformat to work on a phone screen aren’t available in an email context.
I haven’t figured out how to make that limitation apparent in the editor, so you can actually add three or four column layouts when creating content. They will just show up as stacked two column layouts when you view them in the email template.
You can add custom CSS associated with block classes. And because an Additional CSS class(es) option is available in the editor sidebar for any block, you can target custom formatting code at specific paragraphs or sections of your message.
Here’s one of my experiments with using a background image (the header image from the website) as the background image on an email instead of the regular colored background.

Unfortunately, those customizations at the CSS level will not be reflected in what you see in the editor. However, you will be able to preview them in the email template on your website before sending a message.
The email authoring and editing process is not quite what-you-see-is-what-you-get, as the WordPress editor follows the styles set by your theme, and for example the font size displayed in the editor and the font displayed in email format may be different. The previously documented methods of adding editor stylesheets seem not to work with Gutenberg.
However, the preview you see before sending a message should be very close because it’s a special template that also uses only inline CSS formatting, just like the version sent by email.