How can I check mail is reply mail or simple mail using google api client?

Question

$optParams['maxResults'] = 5; 

$optParams['labelIds'] = 'INBOX'; 

$messages = $service->users_messages->listUsersMessages('sender@mail.com',$optParams);

$messageList = $messages->getMessages();

Got list of mail how can I differentiate reply mail and simple mail using this function ?

Answer 1

You cannot do it directly with users.messages.list

Once you have the message list, you need to perform with each message Id a call to users.messages.get and look at the headers.

Response for simple mail:

"headers": [
    ...

      {
        "name": "Subject",
        "value": "Hello"
      },
      {

    ]

Response for reply:

"headers": [
     ...
      {
        "name": "References",
        "value": "\u003cCAKk+M3QBfT964eMSLRsUziugpF7uK+W7YrMv-kKE=tM4+DPxHw@mail.gmail.com\u003e"
      },
      {
        "name": "In-Reply-To",
        "value": "\u003cCAKk+M3QBfT964eMSLRsUziugpF7uK+W7YrMv-kKE=tM4+DPxHw@mail.gmail.com\u003e"
      },

      {
        "name": "Subject",
        "value": "Re: Good morning"
      },

    ]

Differences:

• A reply subject contains Re:
• A reply contains the header References
• A reply contans the header In-Reply-To