这对我有用：

import win32com.client
outlook = win32com.client.Dispatch("Outlook.Application").GetNamespace("MAPI")
msg = outlook.OpenSharedItem(r"C:\test_msg.msg")

print msg.SenderName
print msg.SenderEmailAddress
print msg.SentOn
print msg.To
print msg.CC
print msg.BCC
print msg.Subject
print msg.Body

count_attachments = msg.Attachments.Count
if count_attachments > 0:
    for item in range(count_attachments):
        print msg.Attachments.Item(item + 1).Filename

del outlook, msg