Question: Linked with my gmail account and synced. --> Issue - I was not able to see the email under some of the customers to whom I have sent email or customer have sent email to my account. Not sure what is the issue.
It could be because of a number of reasons.
a) When you make the initial sync we look 14 days back so if the email is older than that it won be included. Once synced though we keep it for indefinite time.
b) We need to know which customer the email relates to, so if the user you emailed with isn't a contact in Planhat there is a risk of the email not getting synced. Most of the time we're able to "guess" where an email belongs and even create a contact automatically. But sometimes there's just not enough information.