📅  最后修改于: 2022-03-11 14:57:14.432000             🧑  作者: Mango
as.string()
|
+------------MIMEMultipart
| |---content-type
| +---header---+---content disposition
+----.attach()-----+----MIMEBase----|
| +---payload (to be encoded in Base64)
+----MIMEText