Gmail API returning status code 400, error “Mail service not enabled”
问题 I recently started seeing the following error from the gmail API: { "code" : 400, "errors" : [ { "domain" : "global", "message" : "Mail service not enabled", "reason" : "failedPrecondition" } ], "message" : "Mail service not enabled" } Every gmail api call I've tested causes the error, but the following code shows a normal example: public static List<String> getThreadIdsFromRFC822MessageIds(Collection<String> messageIds, User u) throws IOException, NoOauthCredentialsException { List<String>