I am using Outlook Express and when I'm trying to send emails I get the following error:
"An unknown error has occurred. Account: 'Scoil Eimear', Server:
'scanner.scoilnet.ie', Protocol: SMTP, Server Response: '421 4.7.0 Not
allowed.', Port: 25, Secure(SSL): No, Server Error: 421, Error Number:
0x800CCC67".
How can I solve it?