我已经使用Google Email Migration API v2成功迁移了小型测试邮件。但是，在迁移较大的消息时，我收到如下错误：
{
"error": {
"errors": [
{
"domain": "global",
"reason": "conditionNotMet",
"message": "Limit reached.",
"locationType": "header",
"location": "If-Match"
}
],
"code": 412,
"message": "Limit reached."
}
}
我开始偶尔注意到错误，消息大小为 32kb。在大小约为 40kb 时，错误变得一致（没有消息成功）。我已经确认无论我是使用google-api-python-client和我的非标准发现文档还是OAuth 2.0 playground都会发生错误。以下是对小于 32kb 的消息的成功调用和响应：
POST /upload/email/v2/users/jay@ditoweb.com/mail?uploadType=multipart HTTP/1.1
Host: www.googleapis.com
Content-length: 6114
Content-type: multipart/related; boundary="part_boundary"
Authorization: Bearer <removed>
--part_boundary
Content-Type: application/json; charset=UTF-8
{
'isInbox': 'true',
'isUnread': 'true'
}
--part_boundary
Content-Type: message/rfc822
From: <admin@jay.powerposters.org>
To: <admin@jay.powerposters.org>
Subject: test growing message sizes
Date: Wed, 17 Jul 2013 10:40:48 -0400
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
<last line repeated ~50 times>
--part_boundary--
HTTP/1.1 204 No Content
Content-length: 0
Via: HTTP/1.1 GWA
X-google-cache-control: remote-fetch
Server: HTTP Upload Server Built on Jul 8 2013 15:32:26 (1373322746)
Etag: "S82oyh6kQMvIt9YE14Ogc8RmmsQ/vyGp6PvFo4RvsFtPoIWeCReyIC8"
Date: Wed, 17 Jul 2013 17:35:13 GMT
这是~150kb的失败消息的样子：
POST /upload/email/v2/users/admin@jay.powerposters.org/mail?uploadType=multipart HTTP/1.1
Host: www.googleapis.com
Content-length: 189946
Content-type: multipart/related; boundary="part_boundary"
Authorization: Bearer <removed>
--part_boundary
Content-Type: application/json; charset=UTF-8
{
'isInbox': 'true',
'isUnread': 'true'
}
--part_boundary
Content-Type: message/rfc822
From: <admin@jay.powerposters.org>
To: <admin@jay.powerposters.org>
Subject: test growing message sizes
Date: Wed, 17 Jul 2013 10:40:48 -0400
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
<last line repeated ~1500 times>
--part_boundary--
HTTP/1.1 412 Precondition Failed
Content-length: 240
Via: HTTP/1.1 GWA
X-google-cache-control: remote-fetch
Server: HTTP Upload Server Built on Jul 8 2013 15:32:26 (1373322746)
Date: Wed, 17 Jul 2013 16:57:23 GMT
Content-type: application/json
{
"error": {
"errors": [
{
"domain": "global",
"reason": "conditionNotMet",
"message": "Limit reached.",
"locationType": "header",
"location": "If-Match"
}
],
"code": 412,
"message": "Limit reached."
}
}