The error message says, 'Outlook cannot find the server etc.' 'Error Code: 3170'. I'm not sure that MS's theory is fully correct because sometimes I get the send failures on the first message sent. If I leave it in the outbox, it will eventually send.
Furthermore, I cannot find any Verizon support for Outlook 2011 for the MAC! Once again this is 'intermittent' such as 4 messages will go and then the 5th will not. MS suspects that the server doesn't like that and rejects messages within a certain time period. Apparently, every email that is sent, sends a User Name and Password to Verizon's server. Everywhere I look for assistance, including Microsoft, Apple and Verizon, no one has found anything wrong other than Microsoft suspects that Verizon's server doesn't like too many logins and passwords in a set period of time. Ever since Verizon changed its POP server settings, I am getting intermittent send failures from MS Outlook for MAC 2011 even though I made the correct port changes and SSL options in Outlook 2011.