将电子邮件从一个Gmail邮箱导入到另一个Gmail邮箱

Question

I have 2 Gmail accounts, and I use one ("gmail1") to forward all e-mail to the other one ("gmail2"). This works fine, but I discovered recently (after years!) that in fact, Gmail does not forward all my e-mail, but only the e-mail it considers not to be spam. Therefore, checking my spam folder in gmail2 for missing e-mails, I have often blamed senders, when really the e-mail had gotten lost on gmail1. I want to solve this programatically, by regularly checking for spam e-mails in gmail1 and importing them into gmail2 (then I'm fine with gmail2 categorizing as spam or not, as long as the mail makes its way there). I'm only a very amateur programmer, and so far thanks to some samples from the gmail API docs, I've managed to log in to my accounts, and retrieve some messages corresponding to a query, including for example recent spam e-mails. However, I'm struggling with the "import" concept and how to use it. There are no Python examples for this, and I couldn't solve the problems I'm facing.

Where I am right now: - if I "get" a message from gmail1 and attempt an import_ call on gmail2, using the message I just retrieved, I get an error because threadId is not allowed - if I do the same and then "del message['threadId']" then the error becomes error 400 : 'raw' RFC822 payload message string or uploading message via /upload/* URL required. I've seen that there are some situations where upload is required, but I am completely lost as to what I should do to make this work.

Here's what I have so far (sorry for the very hacky style):

# skipping imports
SCOPES = ['https://www.googleapis.com/auth/gmail.readonly','https://www.googleapis.com/auth/gmail.modify']


def getMessage(service, user_id, msg_id):
  """from gmail API examples"""
  try:
    message = service.users().messages().get(userId=user_id, id=msg_id).execute()
    return message
  except errors.HttpError as error:
    print ('An error occurred:' , error)


def listMessagesMatchingQuery(service, user_id, query=''):
    """from gmail API examples"""
    # skipping some code
    return messages

def login(accountId):
    """from gmail API examples, adapted to handle 2 accounts"""
    # skipping some code
    return build('gmail', 'v1', credentials=creds)

def importMessage(service, user_id, msg):
  """my daring attempt at using import, without any Python sample to use as a basis"""
  try:
    message = service.users().messages().import_(userId=user_id,  body=msg).execute()

    return message
  except errors.HttpError as error:
    print ('An error occurred:' , error)


if __name__ == '__main__':

    service_gmail = login('gmail2') 
    service_dnt = login('gmail1')

    messages = listMessagesMatchingQuery(service_dnt,"me","in:spam is:unread after:" + str(int((datetime.now() - timedelta(hours=12)).timestamp())))
    # this gets me some recent unread spam messages

    m=getMessage(service_dnt,"me",messages[0]['id'])
    # now I have a full message - I'm just investigating for now so the first message is enough

    del m['threadId']
    # if I don't do that, the error I get is that threadId is not allowed here, so I remove it

    imported = importMessage(service_gmail,"me",m)
    # this now gives me error 400 : 'raw' RFC822 payload message string or uploading message via /upload/* URL required

I'd like to find the way to make this work, so that the e-mail appears in gmail2 as if it had been received by gmail2 directly (though I would like to keep the To: address, as I use a catch-all on gmail1 and want to know which e-mail address the e-mail was directed to). But right now, I get only errors about having to use upload; I'm not sure if that's what I really should be doing, and if it is , I have no idea how.

Thanks a lot in advance for any help!

Answer 1

In the end I managed. I had missed the fact that there are 2 ways to "get" messages, a simple one and a "raw" one. With the "raw" way to access the message, I can use the import_ function easily:

message = service_dnt.users().messages().get(userId="me", id=messageId,format='raw').execute()
imported = importMessage(service_gmail,"me",{'raw': message['raw']})

whereby the importMessage function is unchanged vs. the original code I posted.