Recently, Verizon upgraded its residential email servers to use secure, i.e., encrypted, connections. This is very important to the security of your email, particularly if you use public wireless networks.
Here are the new settings, as copied from http://www22.verizon.com/residentialhelp/fiosinternet/email/setup+and+use/questionsone/86782.htm
Mail server settings
Now would be a good time to change to the more secure settings, AFTER taking note of your current settings, in case there is a problem. These new settings should work with Outlook, Outlook Express, and Thunderbird, as well as on Android phones and the iPhone. Among possible causes of incompatibility with the more secure settings include blocked ports at the firewall, VPNs and proxies.
If you don’t feel comfortable reconfiguring your email software, you should ask your IT support person for assistance.