Email has been progressively used as a means for providing therapeutic guidance and support for cognitive behavioural treatment (CBT) self-care programmes. Many aspects of the use of email in self-care need to be explored such as the content of therapists' emails. Such information would optimise the delivery of self-care treatments. To date no study has looked at the content of the therapists' emails. We analysed the content of emails (n = 712) sent by therapists to participants (n = 71) of a randomised controlled trial (RCT) of internet-based CBT with email support for bulimic disorders. 14.7% of the emails therapists sent contained at least one CBT comment, while 95.4% had at least one supportive comment and 13.6% had at least one technical comment. The mean time spent on providing email support to each participant across the complete programme was 45 minutes. Emails sent by therapists were mainly supportive in content, with only a small amount of time being required by therapists to provide email support. Copyright © 2011 John Wiley & Sons, Ltd and Eating Disorders Association.