Mac Book (or wireless) Email

I ask this question a few hours ago, but being new to these forums, I put it in an improper location, unaware of this topic's existence. I apologize. Here is my issue:

I have a Mac Pro, and I just recently acquire a Mac Book. I have two separate emails; one is for work and the other is for everything else.

For some reason, the mail system on my Mac Book will not allow me to send messages (and yes, everything is set up correctly, exactly the same as my properly functioning Mac Pro). This issue effects both email accounts. Do Mac Books have a default setting to prevent out going data? Are there any issue that occur from being wireless? Does the "Mobile Me" have any impact on this (meaning it's a requirement for Mac Book mailing)? Does it matter that I have two computers using the same email accounts?

My providers are www.1and1.com and www.got.net (local company).

The error message I receive is that I "can't send messages using the server (server's description name)," as if I enter the wrong information, or if my hosting server was down. However, since I have triple checked each email account (recreating both accounts each time) and have match everything from my working accounts (down to the exact port numbers), I assume it is more of an issue of being wireless than a user error.

If you have any helpful advise, I would greatly appreciate it. Thank you.