To Fix this problem follow the steps:
1- Sign into the old Gmail account first ( the one you are attempting to get mail from )
2 - You may require to Enable less-secure Apps for that account >> https://www.google.com/settings/security/lesssecureapps
3 - Then go here: https://accounts.google.com/b/0/DisplayUnlockCaptcha
4 - Then sign in to the zoho account ( the one you are attempting to get mail into ) and go to Settings/Mail Account/Add POP3 Account within the 10 minute window you are approved.
5 - Fill out the POP3 details with your G-Mail information; xxx[at]gmailcom; username[at]gmailcom
pop.gmail.com 995 SSL; username[at]gmailcom gmail password
6 - Click test and it must authenticate and move to the next step which is smtp.
smtp.gmail.com 465 SSL; username[at]gmailcom gmail password
In case the above suggestion doesn't perform, there are more options listed here https://support.google.com/mail/answer/78754 for example hanging the password on the account you want to get FROM
In case you use 2-step on the account you need to get FROM then you require to make an application specific password »
https://support.google.com/accounts/answer/185833?hl=en or just turn it off.