#attachments 5 articles

• A drop box for sensitive files — a document library can't do it, a list with ReadSecurity 2 and attachments can (measured, including the direct attachment URL)gotchas / permissionsGiving someone write access to a protected library folder also lets them read every file in it; a list with ReadSecurity = 2, Contribute for the senders and Edit for the reviewers lets people send files they alone can…
• A missing attachment returns 400, not 404 – an "is it there?" check by status code reads "not there" as a failuregotchas / rest-apiAttachmentFiles('name') on a missing attachment returns 400 ArgumentOutOfRangeException; check existence from the attachment list
• A screenshot pasted into a support form is too big for /me/sendMail — shrink it client-sidegotchas / graphInline base64 attachments share a ~4 MB request budget; shrink bitmaps in a canvas, cap the total, and remember mailto: fallbacks carry no attachments at all
• Adding an attachment changes the item's ETag – the next MERGE with the old ETag fails with 412gotchas / rest-apiAttachmentFiles/add changes the item ETag; re-read before an IF-MATCH update
• Upload a generated image as a list item attachment (no file picker)snippets / restCanvas charts, placeholder banners, QR codes — AttachmentFiles/add takes a raw ArrayBuffer; the item must exist first