当我使用SMTP课程发送电子邮件时，我在Outlook中打开邮件时会收到无标题附件。除Outlook外，此附件不会出现在其他邮件中。
格式如下：
by mx.google.com with ESMTPSA id zv3sm87988681pab.20.2014.05.28.05.01.34
for <multiple recipients>
(version=TLSv1.2 cipher=ECDHE-RSA-RC4-SHA bits=128/128);
Wed, 28 May 2014 05:01:36 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=gmail.com; s=20120113;
h=date:message-id:from:to:content-type:mime-version:subject;
bh=PgZzyEIzglPFfZsphJX1BrHG0bPbP9AXqR++d0Gj8Oo=;
b=l2bri26it0L8RjTFANJYAPoHTCElx3T7r+ycMhOXj28vR9j9vxrGv+ZPvjoWybO1wd
zS11DajkWoKY1jKvUrJ70tfx5CqNtFs5kb5UnUwEm12ODn+x6eWVKt7mbPWn8SWB980R
OFRROKEP4PU5CG56leP9eAhy1nl09rtlC1XOt+2QyEHBmSOx1TE62qWPLvTmMvX89k9S
/Yu9icFRcALtyTSfN+jWe8v8qcPmhNnDxkD+jutPJk3Fv1Cp6zBKcrrjl+xBmxgW7ORQ
sZWf3RXKD5rYon3woCdb3zX+BUgRyloQSbHq/yZ8Z3J1KVQ5+NW9N5otvXepcr74kQyc
wxbg==
X-Received: by 10.68.201.10 with SMTP id jw10mr45530284pbc.25.140127849xxxx;
Wed, 28 May 2014 05:01:37 -0700 (PDT)
Date: Wed, 28 May 2014 17:31:36 +0530
Message-id: <testemail@gmail.com>
From: testemail@gmail.com
To: test@gmail.com
Content-Type: multipart/mixed; boundary=SKPSMTPMessage--Separator--Delimiter
Mime-Version: 1.0 (SKPSMTPMessage 1.0)
Subject: testing
X-ZohoMail: SS_6 SFPD SFPP UW2468 UB6248 FMWL SFP_WHTLST COSF SGR3_1_03044_351
X-ZohoMail-Owner: <testemail@gmail.com>
X-ZohoMail-Sender: xx.140.153.xxx
X-Zoho-Virus-Status: 2
代码
NSDictionary *plainMsg = [NSDictionary
dictionaryWithObjectsAndKeys:@"text/html",kSKPSMTPPartContentTypeKey,
messageBody,kSKPSMTPPartMessageKey,@"8bit",kSKPSMTPPartContentTransferEncodingKey,nil];
emailMessage.parts = [NSArray arrayWithObjects:plainMsg,nil];
[parts addObject:plainMsg];
提前致谢。