Signatures and logos

A signature exists once and is used everywhere: by the webmail composer, by the review of drafts, and by workflows that sign what they send. Signatures live in the Address book, tab Signatures; the composer also opens them with Manage signatures.

• A Personal signature belongs to you. An Organisation signature is offered to every member, and only administrators create it (Organisation signature (offered to everyone)).
• Each owner has one default signature at most (My default signature). The composer pre-selects it, and drafts written for you use it, unless a card or a default chooses another one.

See Address book for how a signature is chosen for a given recipient.

Adding a logo

In the signature editor, click Insert an image / a logo and choose a file.

Rule	Value
Formats	PNG, JPEG, GIF. SVG is refused: most email clients do not display it.
Weight	200 KB at most
Size of the file	1200 × 1200 pixels at most
Display width	240 pixels at most; a wider logo is shown smaller, with its proportions kept

The image is stored in your Loop & Roll instance. In the editor, it is displayed from the instance itself, for signed-in members only: nobody outside sees that address.

An image pasted from a website, or written as a web address, is not kept: the editor says so, and an API call that sends one is refused with signatures.external_image. Such an image would be blocked by the recipient's email client, which hides remote images by default, exactly as Loop & Roll does for the emails you receive.

How the logo reaches the recipient

When an email leaves Loop & Roll, the logo is embedded in the message itself, as Outlook and Gmail do: it travels as an inline part with a Content-ID, and the body refers to it as cid:. No link to a remote image is ever sent. As a result:

• the logo displays as soon as the message opens, without the recipient having to allow images;
• it appears in the body, not in the list of attachments;
• it works the same whatever the mailbox: Gmail, Microsoft 365, IMAP/SMTP, and the demo mailbox, which keeps a copy of what it would have sent.

This applies everywhere a signature is applied:

• Webmail composer: send, draft, reply and forward;
• Review: the logo of a draft shows in the preview, does not count as an attachment, and stays when you edit the draft before sending it;
• Workflows: the Send node, including what Compose (AI) prepares for it. Compose (AI) writes text: its signature is the text one, and the logo is added by Send when it signs the message.

Limits

• Deleting a signature does not delete its image from the instance: an image weighs 200 KB at most, and the same file uploaded twice is stored once.
• An email already sent keeps its logo: it is inside the message.