upgrade deps; rewrite smtp session

vendor/github.com/jhillyerd/enmime/options.go

@@ -27,3 +27,64 @@ type multipartWOBoundaryAsSinglePartOption bool
 func (o multipartWOBoundaryAsSinglePartOption) apply(p *Parser) {
 	p.multipartWOBoundaryAsSinglePart = bool(o)
 }
+
+// SetReadPartErrorPolicy sets the given callback function to readPartErrorPolicy.
+func SetReadPartErrorPolicy(f ReadPartErrorPolicy) Option {
+	return readPartErrorPolicyOption(f)
+}
+
+type readPartErrorPolicyOption ReadPartErrorPolicy
+
+func (o readPartErrorPolicyOption) apply(p *Parser) {
+	p.readPartErrorPolicy = ReadPartErrorPolicy(o)
+}
+
+// MaxStoredPartErrors limits number of part parsing errors, errors beyond the limit are discarded.
+// Zero, the default, means all errors will be kept.
+func MaxStoredPartErrors(n int) Option {
+	return maxStoredPartErrorsOption(n)
+}
+
+type maxStoredPartErrorsOption int
+
+func (o maxStoredPartErrorsOption) apply(p *Parser) {
+	max := int(o)
+	p.maxStoredPartErrors = &max
+}
+
+// RawContent if set to true will not try to decode the CTE and return the raw part content.
+// Otherwise, will try to automatically decode the CTE.
+func RawContent(a bool) Option {
+	return rawContentOption(a)
+}
+
+type rawContentOption bool
+
+func (o rawContentOption) apply(p *Parser) {
+	p.rawContent = bool(o)
+}
+
+// SetCustomParseMediaType if provided, will be used to parse media type instead of the default ParseMediaType
+// function.  This may be used to parse media type parameters that would otherwise be considered malformed.
+// By default parsing happens using ParseMediaType
+func SetCustomParseMediaType(customParseMediaType CustomParseMediaType) Option {
+	return parseMediaTypeOption(customParseMediaType)
+}
+
+type parseMediaTypeOption CustomParseMediaType
+
+func (o parseMediaTypeOption) apply(p *Parser) {
+	p.customParseMediaType = CustomParseMediaType(o)
+}
+
+type stripMediaTypeInvalidCharactersOption bool
+
+func (o stripMediaTypeInvalidCharactersOption) apply(p *Parser) {
+	p.stripMediaTypeInvalidCharacters = bool(o)
+}
+
+// StripMediaTypeInvalidCharacters sets stripMediaTypeInvalidCharacters option. If true, invalid characters
+// will be removed from media type during parsing.
+func StripMediaTypeInvalidCharacters(stripMediaTypeInvalidCharacters bool) Option {
+	return stripMediaTypeInvalidCharactersOption(stripMediaTypeInvalidCharacters)
+}