Your email address that you use back home
can receive email, but cannot send.

If you have an email address through a connection provider, you are generally required to connect through that connection provider, and log onto their system, before you can SEND email through that account. You cannot connect to the internet outside of their system, and SEND email through their system. This is the price you pay for having an address that is provided by a connection service.

That said, some may allow it. If they do, you will need to call their tech support and change your authentication settings whenever you plan to connect differently.

Some providers offer a web-mail interface which allows you to access your email  through your web browser, instead of your email program.  A Webmail interface, like the one offered by BorderWeb.Net, is convenient when you wish to access your email account on a computer that is not set up with your email address.

If you travel, and connect in different ways, it is far more convenient to get an email address that is not associated with a connection provider. One that works with any connection, anywhere, using your favorite email program.

BorderWeb can provide you with such an email address. The price is nominal.