When ServiceNow has custom tables in use and attachments needs to be sent through, default sys_id mapping cannot be used. Target URI is usually the import set table, but another, usually a default entity, is created in ServiceNow. Following modification is required for the attachments.upload.attachment.uri system configuration:
It is described in ServiceNow adapter as follows by default:
Placeholders for entity type and sys_id needs to be replaced with the targeted entity type (if hard-coded) or an outbound attribute from rule mappings e.g.:
Please note that conversation attributes cannot be referred to in system configuration.