Can't send emails

[#1]

from free wifi in hotels,  I get a return message quoting
'550 relay not permitted for your IP'
I'm guessing this a setting to prevent spam? I use outlook and windows 7. I can receive emails ok.

[#2]

Yes, reading should be OK.
For sending you need to use SMTP Authentication if you are not using a Plusnet connection as when in a hotel. Set up details for this depend on which version of Outlook you are using. See Send mail from any connection (SMTP Authentication) on this Help & Support - Email Setup Guides page. Authentication also works on a Plusnet connection so needn't be removed for home use.
However since usernames and passwords are transmitted in plain text I'd be wary of using this on a free wi-fi connection. Webmail is less convenient but is secure.

[#3]

Thanks for taking the time to reply I will follow the link and have a read.