This is most likely due to your colleague using a different email address that is not associated with their CRM user profile.  

The email has not been recognised against the users profile BUT it has recognised your own email address which is associated with your own user profile and so it has associated the email with your user profile instead of your colleagues. 

Please confirm which email address your colleague used to send the email from and provide this information to our Support Desk.

It is very important that all users have logged any email addresses that they use to send out email against their CRM user profile, making sure that their main email address is set as the default email, which is where any CRM task or event reminder emails will be sent to. 

Please click here to see how to add additional email addresses against a CRM user profile.