You're having trouble with your SMTP Server settings.
Your e-mail program has two kinds of settings; one that handles INCOMING MAIL, and one that handles OUTGOING MAIL. To your e-mail program, these are very different evolutions and it talks to different servers to get the job done.
Your INCOMING server is one of our POP or IMAP mail servers, or perhaps even your own corporate Microsoft Exchange server if you are a Store and Forward client. You're already receiving mail, so we don't need to inspect these settings.
We need to look at your OUTGOING settings, because you're having trouble sending mail.
Open your e-mail program and look at your account settings. You should see a place to enter your "OUTGOING MAIL SERVER" or your "SMTP SERVER". (SMTP stands for Simple Mail Transfer Protocol)
If you have a POP or IMAP account with us, then your OUTGOING MAIL SERVER should be:
smtp.yourdomain.com - OR - mail.wddx.net
You will need to check off "My outgoing mail server requires authentication", and then tell it to "use the same settings as my incoming mail", or something to that effect. (Mail programs vary)
If this doesn't work, then your Internet Service Provider might be blocking you from using our service for outgoing mail. You may need to contact your ISP and use their outgoing mail server. Bellsouth, for example, would use "mail.bellsouth.net", and Comcast would use "mail.comcast.net". Most ISPs do NOT require "my outgoing mail server requires authentication" since you connect to the internet via their network.
If you use a satellite connection, as many yachts do, then you would absolutely want to use your ISP's SMTP server.