Forgive us if I get too basic here, but I thought I'd spell as much of it ought as I can.
For each e-mail account, you need the following settings:
User information (Your name and e-mail address)
Logon Information (User name and password)
Server information (incoming and outgoing mail servers)
Your ISP tech support staff is used to providing this information, but they are doing it based on the assumption that you are using their incoming and outgoing mail servers.
Since you have your own domain, though, you don't want to use their mail servers. You want the mail to go through your own mail servers (i.e. mail.mydomain.com)
There's a catch, though, many ISPs won't let you use an alternative outgoing mail server. This is a Good Thing, because it allows them to ensure that only people with accounts on their system are able to send e-mail through it.
So what does that do to your settings?
User information is the easiest: your name and e-mail address
Logon information: Your username and password for your Paravel Solutions account. However, remember what I wrote in the earlier message. If you are using your main cpanel login name, omit the "@mydomain.com"
Incoming mail server: mail.mydomain.com
Outgoing mail server (SMTP): Ask your ISP, or copy what you're using for your e-mail address under your ISP.
That's right--your outgoing mail server is through your ISP, even though it is for a Paravel Solutions hosted e-mail account under your own domain.
Depending on the current settings required by your ISP, you may also need to provide authentication information for the SMTP outgoing server. In my case, that is my username and password for my ISP account.
I can't use the same settings as my incoming mail server, because I use my cpanel username and password for that--that's to authenticate with Paravel; Solutions.
I hope I haven't totally confused you. Just try and keep in mind the pieces:
You have an incoming mail server and you apparently have all the settings correct for that.
You have an outgoing mail server, and that needs to be your ISP's mail server name, and your authentication information for your ISP