No Login Methods Supported with Zentyal Mail Server

No Login Methods Supported with Zentyal Mail Server

We are working with Service Desk Plus using Zentyal mail account, but unfortunately incoming mail server is not connect, 


We tried with different kind of Email type of Port as IMAP / IMAP TLS  but always appears the message: "No Login Methods Supported".

May you have any idea about it?

Thanks in advance

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