Disclosed are systems, methods, and non-transitory computer-readable storage media for managing email attachments in an online content management system. In some implementations, a messaging client can receive input attaching a content item to an electronic message in a message thread. In response to the input, the messaging client can store the content item in a file system managed by an online content management system, generate a link to the content item, and insert the link in the electronic message. The content item can be shared with the recipients of the electronic message such that the content item can be synchronized across recipient devices by the online content management system. The messaging client on each recipient device and/or the sender's device can present representations of the attachments associated with the message thread in a centralized location on a GUI of the messaging client.