Thanks for your answer.
This is the error:
"Unknown error. Account: 'mail.mastersoft3000.info', Server: 'mail.mastersoft3000.info', Protocol: SMTP, Server response: '421 Cannot connect to SMTP server 184.168.85.176 (184.168.85.176:465), connect error 10061', Port: 587, Secure (SSL): No, Server Error: 421, Error number: 0x800CCC67"
As you can see, Secure (SSL) is NO (becouse it is not checked in my email client).
The strange thing is that it shows "(184.168.85.176:465)" pointing to port 465, but next says "Port: 587"
The issue is that if I Turn Off Avast or with Avast Turn On but UNCHECKED "Scan outbound messages" option in Mail Shield, I can send emails without problem, so I think I must configure something in Avast, but I don´t know wath to do.
Any idea ?
Thansk for your help.