Yes, you can always access webmail.
Webmail allows you to access your email from any computer in the world as long as it's connected to the internet. All you'll need is to know your access password and your email address.
The system is very similar to other popular webmail services such as Hotmail or Gmail.
In our case, you'll have three options available: Horde, Squirrelmail, and RoundCube. Each one with its pros and cons. So the choice between them is a matter of personal preference.
Keep in mind that if you want to use the webmail service effectively, all your accounts on computers, tablets and phones should be configured to use the IMAP connection protocol. Avoid the POP3 protocol at all costs.