The system will recognize the activity related to the actions done within the Liondesk account. The last email that went out to him from the database was on 12/24 and he opened the email that same day.
The other emails listed in the activity timeline dated after 12/24 are from your 3rd party email account. Liondesk does not recognize that as being an "activity" done within the platform which is why the date does not match.
I hope this makes sense š Let me know if you have any questions.
I do think it would be great to have those emails be recognized as activity. You might want to submit your suggestion by going to the ideas page