Occurs when the SMTP server doesn't require authentication
(authenticationType == null).
The javadoc for ServerSettings says that both authenticationType and
connectionSecurity may be null.
AUTOMATIC = "Automatic"
PLAIN = "Normal password"
CRAM_MD5 = "Encrypted password"
SMTP also uses LOGIN. No localized text was associated with that because
a future commit will remove that option.
(The text is similar to that of Thunderbird's)
