It's important to not ignore and read the limitations below.
Actions performed on past emails in the email client do not sync to Concord CRM.
Draft folders are not supported and synced nor you can send or create messages via Draft folder.
When using Gmail connection type, you cannot apply labels like in Gmail interface, you can only move messages to specific labels like in regular mail client.
When user is deleted, personal email accounts are deleted too with all it's messages.
Changes to folders are synchronized hourly.
Connection of type IMAP cannot sync remotely renamed folders, if renamed, the folder will be deleted from Concord CRM database and the new folder will be created and will sync again the messages.
Connection of type IMAP cannot sync new folders, you will need manually to edit the account and re-test the connection to show the newly added folders from the remote server.
For connection of type Outlook FROM HEADERS cannot be configured, the from name will be shown as in Outlook web.
Don't use IMAP connection to connect to Gmail account via the IMAP protocol because messages will be duplicated and probably your server storage will be filled in time.