I've tried to login to my zoho mail with Spark (an Email client), Mail.app (the macOS built-in Email client) and Gmail "Send mail as" feature. All of these methods wouldn't allow me to login, saying:

"Unable to verify the username and password"

"Unable to authenticate with the current session's credentials"

"The recipient server did not accept our requests to connect. Learn more at https://support.google.com/mail/answer/7720 [mx.zoho.com 204.141.42.121: timed out], code: 0"

Is there a downtime on zoho side? Because this prevents me from using my Email account on desktop.

PS: I'm using zoho mail for years so I'm very sure that my DNS settings are fine.