Multiple recipient email addresses is not working for xsl & PDF Attachment

Question

multiple recipient email addresses is not working properly when
to list has some external email address and sending xls and PDF file as an attachment.
Test Scenario:
(A) Create mail target activity
1)To email : use the multiple email id with some external domain (ex.
[email protected] ,[email protected], [email protected])
2)File attachment with .xls file and this file is sending to mail target as an inputstream(at runtime)
3)Use all other valid parameter in activity.
(B) Create a process flow File source to mail target
Execute the process flow.
Actual Result: Mail is received by every email account. Only external email account get correct file but other email account(as ([email protected])) attachment files
displaying message
�abc.xls� can not be accessed. The file may be read-only, Or you may be
trying to access a read only location. Or, the server the document is stored on
may not be responding.�
When i trying to open xls and PDF file
Expected Result:
All type of file attachments should be supported with all valid email address
(servers).
Pls help me about this senario:
What is problem in this case:
I am sending code
Session session =getSession(host,port,secure);
session.setDebug(this._debug);
               Transport trans = connect(host,port,session,userID,password);
               Message message = new MimeMessage(session);
               InternetAddress[] iAddr = null;
               message.setFrom(new InternetAddress(fromName));
               iAddr = InternetAddress.parse(toUserName, true);
               message.setRecipients(Message.RecipientType.TO, iAddr);
               message.setSubject(subject);
               //BodyPart messageBodyPart = new MimeBodyPart();
               Multipart multipart = new MimeMultipart();
               MimeBodyPart messageBodyPart=null;
if(dataLocation!=null && dataLocation.equalsIgnoreCase("ATTACHMENT")){
                    String tmpName=fileName;
                    if( inputstream != null)
                              tmpName = makeAttachment(fileName,inputstream);
                    messageBodyPart = new MimeBodyPart();
                    DataSource source = new FileDataSource(tmpName);
                    messageBodyPart.setDataHandler(new DataHandler(source));
                    fileName = fileName.replace('\\', '/');
                    fileName = fileName.substring(fileName.lastIndexOf('/') + 1,
                              fileName.length());
                    messageBodyPart.setFileName(fileName);
                    multipart.addBodyPart(messageBodyPart);

Answer 1

First, when sending your message, the filename should be a simple
filename, not containing any directory names.
It sounds like your mail server might be doing some special
processing of attachments, perhaps to prevent viruses.