* lisp/net/sieve-manage.el (sieve-manage-ignore-starttls):
Rename from sieve-manage-ignore-broken-tls. If it is set,
sieve-manage will never use STARTTLS even if the server says
it is capable (but may be broken).
* lisp/net/sieve-manage.el
(sieve-manage-ignore-broken-tls): New user option.
(sieve-manage-open-server):
Don't test STARTTLS capability if the option is set (bug#24422).