---
title: "Attachments"
description: "Pick them with the paperclip or paste them in. A pasted image lands in the body rather than the file list, and a file dragged onto the composer is not attached at all. On an OpenEmail mailbox incoming files sit in object storage, one object each, and opening a thread pulls every one of them."
url: "https://openemail.uk/docs/knowledge/writing/attachments"
area: "Knowledge base"
category: "Writing & sending"
status: "live"
---

# Attachments

Pick them with the paperclip or paste them in. A pasted image lands in the body rather than the file list, and a file dragged onto the composer is not attached at all. On an OpenEmail mailbox incoming files sit in object storage, one object each, and opening a thread pulls every one of them.

## Details

- The paperclip takes several at once and offers images, PDF, Word, Excel and .txt; pasting attaches whatever else the clipboard is holding. PNG, JPEG, GIF and WebP are the exception: pasted or dropped into the message body they are embedded there as an inline image rather than attached. Any other file dropped on the composer is not picked up at all.
- Two ceilings, and they are deliberately different numbers. Files carried inside the message are capped at 5 MB in total, and the assembled message itself (body, headers and every attachment encoded) is measured separately against 30 MB. Both apply wherever the message was written: the composer, the API and the assistant are all held to the same pair. Files sent as download links are counted by neither. Once a files domain is active, a message whose files come to more than 2 MB carries them as links on its own, and the API can link a file already in the workspace at up to 100 MB each and 250 MB a message.
- Images can be compressed on the way out (Low, Medium or Original), and already-attached files are re-processed when you change it.
- Opening a thread pulls the bytes of every attachment on every message in it, since each message asks for its files as it renders, before you have clicked one. A message you sent keeps its attachments too, so downloading one back out of Sent works. Two things still come back empty: anything sent before that was true, and a file since deleted from Files.