i am brand new to plesk
when i am using outlook with plesk 6 i can download emails ok.. but the problem i can't send any emails using outlook...
i think the problem is in the smtp

The message could not be sent because one of the recipients was rejected by the server. The rejected e-mail address was 'xxx@xxx.com'. Subject 'Re: New Observation', Account: 'xxxxx', Server: 'xx.xxx.xxx.xxx', Protocol: SMTP, Server Response: '553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1)', Port: 25, Secure(SSL): No, Server Error: 553, Error Number: 0x800CCC79

please help

The most common reason for this error is failing to have SMTP Authentication setup properly in your email client. In outlook go into tools > accounts, select the mail account then click on Properties. Click on the Servers tab then at the bottom click on the box that says "My server requires authentication". In the settings "Use same settings as my incoming mail server" should be selected.

Just click apply then ok to close out and try it again.

https://members.ev1.net/rsmembers/english/support/ev1servers_plesk/plesk_OE.asp

plesk comes with closed relay by default..

you have to set relay on plesk to be open with authorization

login to plesk as admin
goto mail

check smtp, pop and set lock time with 20min

click set..

then from your outlook client check my server requires smtp to authoirze