You probably need to change your outgoing server options so Outlook can find the outgoing server that the other location is using. You will need to get that info. from their IT or check with anyone that currently sends email from that location. All they will need to do is open their email account info. and see what their settings are.
In Outlook try going to Tools, Options, Mail set up, email accounts, and change your Outgoing mail server (SMTP) to match the locations SMTP pop settings.
If you need to access your email from various locations on a regular basis this can be a real pain to have to do each time. In that case I would suggest setting up a gmail account and having your Outlook messaged forwarded to your gmail account. Another option you email provider may be web based in which case you can log directly onto their site to access your email. Check with your ISP.
Best of luck.