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.

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, in every language, unless a language has its own. In a rich text / HTML layout, open a translation and set its Attachments card to Different attachments for this language; in a visual layout, each language's design carries its own Attachment blocks. A German invoice for German customers and an English one for everybody else is one layout. See Send emails in your customer's language.

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.

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

Open the media picker anywhere you insert an image or attachment - the logo field in Branding, or Insert image in a layout. Every file has a delete button in its corner. Confirm, and the file is removed from storage for good, which also frees up your storage allowance.

If a file is still used - as an attachment, an image block, a header logo, inside an image-with-text block, or by a shared header or footer preset - the delete is refused and the message names what is using it. Because the media picker lets you reuse one file in many places, this check is what stops clearing out one layout from quietly breaking another email that is still sending. Remove the file from the layouts or presets named, then delete it.

The same is available over the API: GET /api/v1/files?usage=true shows which files nothing references, and DELETE /api/v1/files removes one with the identical check. See REST API reference.