Outside of the USA there will be problems. See
and note in particular this paragraph:
"Additionally, we have implemented measures to prevent future unauthorized access attempts which may affect your ability to access your Verizon.net email from locations outside the U.S. If you experience difficulty reaching your Verizon.net email account, you can always access it online at mail.verizon.com or through the Verizon My FiOS app for mobile devices. For further information see the Verizon Webmail FAQs."
In some cases you can get them to whitelist the IP address.