Zoho
 CRM provides a variety of emailing options that users can choose based 
on their requirements. One such option is the Zoho Mail Add-on. With 
Zoho Mail Add-on, you can configure your email client within Zoho CRM 
using either one of the two protocols - POP3, IMAP or by using Gmail 
API.
IMAP -
 It lets you work with emails without downloading them to the computer 
first. IMAP allows storing of emails on remote servers. This two-way 
protocol also allows synchronization of emails among multiple devices.
POP3 -
 POP downloads email to your computer and usually deletes the email from
 the remote server. This protocol does not allow the synchronization of 
emails among multiple devices. If you have more than one device where 
you read your mail, you could see read emails as unread with no 
indication of which you deleted, read or flagged. The folders you 
created on one device won't be replicated on the other devices.
GmailAPI -
 For Gmail users Gmail API is the best choice for authorized access to a
 user's Gmail data. This does not store any of the emails in third-party
 database providing more security and privacy to your emails.
Gmail users can get their emails within Zoho CRM using any of these methods.
One
 main difference is, by using the protocol POP3/IMAP emails are stored 
in Zoho CRM's database whereas the Gmail API does not store the emails 
in Zoho CRM's database. All the emails displayed within your account are
 directly called from the Gmail servers using APIs.
Only when MailMagnet is enabled, some details of the email are stored which included Mail ID (alphanumeric ID), From Address and Mail Received Time.
On setting up the Gmail account using Gmail API, you can:
- Send and receive emails.
 - Contextually view the emails along with the contact details.
 - Share the emails with other users of Zoho CRM.
 - Segregate emails based on three categories in your Gmail account - Deals Closing This Month (CTM), Open Deals, and Customers.
 
Availability
Permission Required
Users with Zoho Mail Integration permission in their profile can access this feature.

 Set up Gmail Account
To set up a Gmail account
- In Zoho CRM, click Setup > Channels > Email.
 - Click Get Started to connect your email inbox.
 - Choose Gmail > API.
 - In the pop-up, enter the Emailaddress and Password of your Gmail account and click Next.
 - In the pop-up, check the access details permission and click Allow.
 - Enable MailMagnet if you want to receive notifications of incoming emails from customers.
 Enable
 Label your email in Mailbox, if required.
Three
 labels will be created in your Gmail account. Emails from contacts will
 be categorized under these labels based on criteria.
- Deals Closing This Month (CTM) - Contacts who have at least one deals closing in the current month.
 - Open Deals - Contacts who have at least one deal in the pipeline. This does not include contacts with deals closing in the current month.
 - Customer- Contacts who have at least one deal closed and won. This does not include email that fall under the above two categories.
 
- Select one of the Email Sharing Permissions.
Based on the option selected, email corresponding to the contacts in your CRM account, will be accessible to other users. - Click Save.
 

Note
- You
 can always deactivate the Gmail API configuration. Since the emails are
 not stored in Zoho CRM’s database, on deactivation, they will not be 
available in a record’s details page.
 - Every 10 minutes emails will be sorted into labels in your Gmail account.
 - When emails are moved to one of the three labels, they will be deleted from the Inbox.
 - If
 emails are moved from one Label to one of these three labels, then a 
copy of the email will be available under the parent label also.
 - Only when MailMagnet is enabled, you will have the option to enable labels for the mailbox.