It appears that Verizon is blocking our mail server. Calls to the online DSL
support center have produced a unique answer to each call. A sampling: there is
no problem; customers with dynamic IP addresses can not use 3rd party email
servers either to read or send mail; ditto but a universal policy; you have
been declared a spam source; hung up on; hmmmm. One call got a guy that
attempted to help.
Any clueful insights appreciated.