I constantly get 'smtp.verizon.net' on port 587 timed out when sending email on Mac Mail. I have outlook loaded too on the same computer and that works so it seemst to be isolated to Mac Mail. Incoming email seems to work, but at times that also fails. I have several accounts set up through gmail and hotmail and they work all the time, its just verizon email for my issue. The settings have been verified several times, so I know its not the email settings. This is getting extremely frustrating to have to use seperate programs and computers to do email.
Can you try updating your outgoing server port to 465?
The server settings should be:
Incoming mail server: pop.verizon.net; Port 995; Uses SSL
Outgoing mail server: smtp.verizon.net; Port 465; Uses SSL
Here's a walk-through for setting up email clients: