Linter for package smtp

[nabbar]

smtp/config.go:281:35: Top level comment should end in a period (godot)
// Client Get SMTP Client interface
                                  ^
smtp/config.go:341:63: Top level comment should end in a period (godot)
// Close Terminate SMTP negotiation client and close connection
                                                              ^
smtp/config.go:356:78: Top level comment should end in a period (godot)
// Check Try to initiate SMTP dial and negotiation and try to close connection
                                                                             ^
smtp/config.go:369:78: Top level comment should end in a period (godot)
// Check Try to initiate SMTP dial and negotiation and try to close connection
                                                                             ^
smtp/config.go:411:35: Top level comment should end in a period (godot)
// GetDsn Return a correct SMTP DSN
                                  ^
smtp/config.go:99:2: missing cases in switch of type TLSMode: TLS_NONE (exhaustive)
	switch tlm {
	^
smtp/config.go:132:2: missing cases in switch of type NETMode: NET_TCP (exhaustive)
	switch n {
	^
smtp/error.go:80:2: missing cases in switch of type errors.CodeError: UNK_ERROR (exhaustive)
	switch code {
	^
smtp/iodata.go:248:2: missing cases in switch of type ContentType: CONTENTTYPE_ALTERNATIVE, CONTENTTYPE_MIXED (exhaustive)
	switch ct {
	^