The email options that Zoho Recruit provides are:

Built-in Email functionality

You can send emails to your contacts from your Recruit account and associate them with your clients and candidates, even if you don't have an email account configured in Recruit. Your Recruit account has 5GB of storage space for each new user.

Zoho Mail Integration

Enable the Zoho Mail integration and set up your email account in Zoho Recruit. Copies of all outgoing and incoming emails are associated with the corresponding Recruit records. You can set up email accounts from popular email clients or use the POP3 protocol to create custom email accounts. With this integration, you can also share emails with other users in your organization's Recruit account. See also: Zoho Mail Add-on. 

You can use POP3 to set up a business email account in Zoho Recruit:

POP3: POP downloads email to your computer and then usually deletes the email from the remote server. This protocol does not allow synchronizing emails across multiple devices. If you read your email on more than one device, you may see read emails as unread with no indication of which you deleted, read, or flagged on another device. The folders you created on one device won't be replicated on other devices.

Mail Magnet

This option is enabled for users who have set up the Zoho Mail integration. It scans your email inbox intelligently and sends instant notifications in Recruit for important emails from clients and candidates that require immediate attention. See also: MailMagnet. 

Zoho Recruit Plug-in for MS Outlook

If you have a Microsoft Outlook account, you can associate it to your Recruit account using the Zoho Recruit Plug-in for Microsoft Outlook. See also: Plug-in for MS Outlook. 

BCC Dropbox

If you have multiple mailboxes for different email addresses which are all used for business communication, emails sent from different email addresses can still be stored and associated with contacts in Zoho Recruit. BCC Dropbox gives you a unique email address for each user in your Zoho Recruit account that can be added as a BCC on emails you send to clients and candidates. This unique email address automatically pulls all the emails sent to your client and candidates into Zoho Recruit. See also: BCC Dropbox.