E-mail authenticating when traveling

Other than the fact that you have a laptop, your question is lacking in information. What OS are you using? Does your laptop have a NIC? Is your laptop currently configured on a LAN? How do you currently connect to the Internet?

Regardless, hotels understand that most people who use their Internet connections do not work for an IT department. Every hotel I have ever gone to that has an Internet port in the room has provided instructions on how to configure your laptop to connect to it. If you are concerned about whether or not you will be able to do this, have the hotel fax you a copy of the instructions. You can then have someone who is more knowledgeable about this go over it with you before you go.

I AGREE with answer 1 in which you need to give more specific information as to what error your getting.

But I will assume you are having the most common error, which is when trying to send mail, you get a 550 error. You can try this one option if your ISP allows it. There is a checkbox in your pop3/smtp server settings, under outgoing mail server "my server requires authetication"

If this doesn't work, you need to use another smtp server that allows you to send mail from any connection.