PC MAPI: Simple MAPI Common Technical Questions and Answers (105964)

SUMMARY

Below is a list of common technical questions and answers about Messaging Application Programming Interface (MAPI), from versions 3.0. 3.0b and 3.2 of Microsoft Mail for PC Networks.

1. Q. Is it possible to send mail without presenting any type of dialog box to users or at least minimizing necessary user input?
   
   A. Yes, mail messages can be sent without providing any user interface if necessary, or you can limit what is displayed. For example, you can create an application that will always CC: another recipient when sending mail or always send an attachment when sending mail.
2. Q. How do I read messages with a MAPI application?
   
   A. Use MAPIFindNext to get the appropriate message, then use MAPIReadMail to pull up the message information.
3. Q. How can I get details about a user?
   
   A. To get address details, call MAPIResolveName on a valid user, then read the MAPI Recipient structure to pull out the user's addressing information. You can also call MAPIAddress to view the information. There is no call to pull and display a block of information for many recipients.
4. Q. Can template information on a user be pulled out as well?
   
   A. MAPIDetails allows you to view the template information but template information cannot be pulled from MAPIRecip.
5. Q. Can multiple MAPI sessions with multiple users be run on one workstation?
   
   A. No. As with mail, it cannot.
6. Q. Can MAPI access folders other than the inbox, For instance, can it move or copy messages from one folder to another?
   
   A. No, this is not possible with Simple MAPI.
7. Q. What is the most common reason for MAPISendMail failing?
   
   A. An incorrectly defined MAPI Recipient, MAPI Message or MAPI File structure. If any field is incorrectly defined, you receive the generic error MAPI_E_FAILURE or a general protection fault.
8. Q. What are the common reasons for failure when sending attachments?
   
   A. There are three probable causes:
   
   
   1. If there is more than one attachment, having more than one at a given position will cause a failure.
   2. An attachment that does not reside within the text of a message will cause a failure.
   3. An incorrectly defined MAPI file structure will cause a failure.
9. Q. Why do I get an ambiguous recipient error when using MAPIResolveName or MAPISendMail?
   
   A. The ambiguous recipient error means that a user name contains characters that can match more than one default address book recipient. If you use MAPIResolveName to resolve a name producing an ambiguous error, you should then use the MAPI_DIALOG flag or call MAPIAddress to resolve it, then use MAPISendMail. Calling MAPIResolvename again will produce the same error.
10. Q. Why do I get the error "Another application has denied your request" when I Exit and Sign Out of Mail and have another MAPI application running?
    
    A. Exit and Sign Out does not work when Simple MAPI applications are running. Mail is "requesting" that the application log out everyone and it cannot, so it fails.
11. Q. What are Interprocess Communication (IPC) message types used for?
    
    IPC messages can be used to send mail to recipients that act upon a specific mail message type. These messages cannot be seen within Microsoft Mail.
12. Q. Can I one-off address with MAPI applications?
    
    A. Yes. Set the Address field in the MAPI Recipient structure to MS:network/postoffice/mailbox or the Name field to [MS:network/postoffice/mailbox].
13. Q. How can I download messages automatically for my "new mail" routine like Microsoft Mail?
    
    A. You can force the download of messages only when using MAPILogon and the MAPI_FORCE_DOWNLOAD flag. To check for mail you could keep track of unread messages when reading messages and maybe include a timer routine to check for messages. There are two ways to poll Mail:
    
    
    • Use Mail for Windows: Select Mail, Options, and enter a time -or-
      
      
    • set PumpCycleInterval=# of seconds in the MSMAIL.INI file