There are a couple issues that may arrize when sending email.
1. On occasion, some internet service providers may block outgoing mail on port 25. You can use port 26 for your Paravel email account as well. To change this, go to your email settings in your mail account. In the outgoing mail server, find the Outgoing Mail Port Number and change it to 26. (This may be in an advanced tab or area depending on the program you are using.) Here are the settings in Outlook Express. Outgoing mail port can be 25 or 26.
2. Another issue is an authentication error. Although our servers do not require authentication, some internet service providers will restrict outgoing mail that is not authenticated. You can work around this issue by going into your internet settings, and checking "My server requires authentication", then click settings, and enter your email address and password in the Username and Password fields.