Workflow Transactional EmailWorkflow Transactional Email

Attachments and images

The app handles two different kinds of file, and the distinction matters.

Images Attachments
Used for Logos, product photos, banners inside the email Invoices, PDFs, downloads sent with the email
Stored Public CDN Private storage
Delivered as A direct URL in the HTML A MIME attachment, or a download link
Max size 10 MB per file 15 MB per file, 20 MB per layout
Types PNG, JPG, GIF, WebP, SVG Any

Images live on a public CDN because that is what mail clients need to render them reliably. Attachments are kept private and always served as a download - they are never made public.

Adding images

Anywhere an image is accepted - the Image block, an Image + Text block, a header logo, or Insert image in rich-text mode - you can either pick from your media library or paste a link.

The media picker lets you search, filter by type, sort, and upload new files by dropping them in. Uploads go straight to storage rather than through the app, so large files do not stall the page.

[!TIP] The same uploaded file can be reused across as many layouts and blocks as you like. Upload your logo once and pick it everywhere.

Adding attachments

In rich text / HTML layouts, use the Attachments card at the bottom of the editor. In visual layouts, add an Attachment block.

Every attachment has a mode:

Mode What happens
Attach The file is sent as a real MIME attachment, inside the email
Link A download link is rendered in the email's footer under "Attachments"

Attachments apply to every email sent from that layout.

Use Link when:

  • The total attached size is over 20 MB. The app blocks the send otherwise and tells you to switch the largest files.
  • You are sending through Microsoft 365, which rejects messages carrying more than 4 MB of inline attachments. The app shows a warning as soon as you cross that line.
  • The recipient's provider is strict about attachment types.

Link-mode files are served through signed, tokenised URLs. If you later delete the file, anyone opening an old link gets a branded "no longer available" page rather than an error.

[!NOTE] The counter on the attachments card shows how much you have attached against the 20 MB limit, and how much is being sent as links. Keep an eye on it - large attachments are the most common cause of a message being rejected by the receiving server.

Storage quotas

Uploaded files count against a per-plan storage allowance:

Plan Attachment storage
Free 500 MB
Starter 2 GB
Grow 10 GB
Unlimited 50 GB

A usage bar in the layout editor shows where you stand. When you hit the cap, uploads are refused with a message telling you to delete files or upgrade. Auto-generated template thumbnails do not count.

Custom fonts

Settings lets you upload a heading font and a body font (.woff2, .woff, .ttf, .otf). Once uploaded, they appear in the font dropdown in the visual builder's Branding tab. .woff2 gives the best client compatibility.

Deleting files safely

Before removing a file the app checks whether any layout still references it - as an attachment, an image block, a header logo, or inside an image-with-text block. Because the media picker lets you reuse one file in many places, this check is what stops a deletion in one layout from quietly breaking another.