Creates a newNet::IMAP object and connects it to the specified
port (143 by default) on the named host. If
usessl is true, then an attempt will be made to use SSL (now TLS)
to connect to the server. For this to work OpenSSL [OSSL] and the Ruby
OpenSSL [RSSL] extensions need to be installed. The certs
parameter indicates the path or file containing the CA cert of the server,
and the verify parameter is for the OpenSSL verification callback.
The most common errors are:
Errno::ECONNREFUSED
connection refused by host or an intervening firewall.
Errno::ETIMEDOUT
connection timed out (possibly due to packets being dropped by an
intervening firewall).