After connecting your email inbox to HubSpot using IMAP, the emails you send from contact, company, or deal records in HubSpot may not appear in your sent folder.
When an email is sent through the CRM, the email's data is actually transferred from HubSpot to your email provider. Your email provider then send the email to the recipient through their SMTP servers.
Some email providers place a copy of the email in your sent folder from the SMTP servers. If your provider does not do this, the email will not be found in your sent folder.
To check if the email was sent successfully, ensure the status of the email activity is Sent.