You have the wrong server. It is smtp.verizon.net.
There is a thread below that includes the correct mail server settings. You might scroll down the list of threads and review it.
Look at the instructions at verizon.com/emailsettings.
The server changes started about the beginning of the year and supposively the old servers were no longer going to work sometimes in or after September.
There are several changes that must be made including the use of SSL and (if you hadn't used SSL before) a port change. There have been hundreds if not thousands of post about users having trouble, but definitely they work for APPLE computers and Devices. Also make sure password is in the clear (Normal) not one of the encrypted options (since its going over a SSL connection that protects it).
i have followed all the steps in the document on verizon main page. i already had changed my apple mail preferences a few months ago. two mornings ago, outgoing mail was fine. two hours later it stopped working. all settings are those recommended.
auto troubleshooting on the verizon site only works with windows OS.
two hours with tech support and it now works. doesn't know why it worked before and then quit working. kudos tech guy