Message cannot be transferred to node SMTP due to connection error(final)

Hi Everyone,

My client's requirement is, mail should be sent from SAP system to their mail ID.

For mailing purpose, client uses mail server rediffmailpro.com.

The outbound details for that mail server are smtp.rediffmailpro.com and port: 587.

I have configured the SMTP with these details in SCOT and also maintained parameter icm/server_port_1 with port no: 587,

but not able to send the mails.

I have tried with port:25 also.

I have a doubt here, can we use this rediffmail server details in SCOT for sending mail from SAP system to required mail ID's ?

or

Is it necessary that we should have a separate SMTP server in the same network where the SAP systems are present ?

Thanks in advance,

Sudhir Sadhu