// Package smtp implements the Simple Mail Transfer Protocol as defined in RFC 5321. // // It also implements the following extensions: // // 8BITMIME: RFC 1652 // AUTH: RFC 2554 // STARTTLS: RFC 3207 // ENHANCEDSTATUSCODES: RFC 2034 // SMTPUTF8: RFC 6531 // REQUIRETLS: RFC 8689 // CHUNKING: RFC 3030 // BINARYMIME: RFC 3030 // // LMTP (RFC 2033) is also supported. // // Additional extensions may be handled by other packages. package smtp import ( "errors" "strings" ) // validateLine checks to see if a line has CR or LF as per RFC 5321 func validateLine(line string) error { if strings.ContainsAny(line, "\n\r") { return errors.New("smtp: A line must not contain CR or LF") } return nil }