MCOIMAPSession *session = [[MCOIMAPSession alloc] init];
[session setHostname:@"imap.gmail.com"];
[session setPort:993];
[session setUsername:@"qiruihua91@gmail.com"];
[session setPassword:@"*******"];
[session setConnectionType:MCOConnectionTypeTLS];
MCOIMAPMessagesRequestKind requestKind = MCOIMAPMessagesRequestKindHeaders;
NSString *folder = @"INBOX";
MCOIndexSet *uids = [MCOIndexSet indexSetWithRange:MCORangeMake(1, UINT64_MAX)];
MCOIMAPFetchMessagesOperation *fetchOperation = [session fetchMessagesByUIDOperationWithFolder:folder requestKind:requestKind uids:uids];
[fetchOperation start:^(NSError * error, NSArray * fetchedMessages, MCOIndexSet * vanishedMessages) {
if(error) {
NSLog(@"Error downloading message headers:%@", error);
}
NSLog(@"The post man delivereth:%@", fetchedMessages);
}];