How to add Zoho Mail to Outlook?

Our startup uses Zoho Mail on our own domain and I want it inside Outlook 2019 next to my other accounts.

The automatic setup keeps failing on the password even though it is definitely correct. What settings does Zoho actually need?

Two Zoho specific hurdles cause exactly your symptom: IMAP is off by default in Zoho and a correct password still fails when two factor is on, because Outlook then needs an app specific password instead.

1

In Zoho Mail on the web go to Settings, Mail Accounts, select your account and enable IMAP Access. Without this every client fails regardless of credentials.

2

If your Zoho login has two factor enabled, generate an app password: Zoho Accounts, Security, App Passwords, create one named Outlook and copy it.

3

In Outlook add the account, and when it fails automatic setup choose to configure manually with IMAP. Incoming: imap.zoho.com, port 993, SSL. Outgoing: smtp.zoho.com, port 465, SSL, with outgoing authentication using the same credentials.

4

Use the app password from step two in place of your normal password wherever Outlook asks. Finish and send yourself a test both directions.

Domain hosted accounts like yours sometimes sit on Zoho's European or Indian data centers, in which case the servers are imappro.zoho.eu or imappro.zoho.in with the matching smtp host. Your Zoho admin console shows which region the org lives in. If the standard hosts time out rather than reject the password, the region variant is almost certainly why.

It was both: IMAP was off and we have 2FA so it needed the app password. Connected on the standard hosts, sending and receiving fine.