POP3 or IMAP for MS Exchange Server?

Question:

I would like to use your product to process mail on an MS Exchange server. Which product should I use; Chilkat MAIL or Chilkat IMAP?

I saw in your examples that I can use both to connect to an Exchange server MAIL with Pop3 and IMAP for a direct login on the server but which one is the best choice? I have an application that should process all the mail that is delivered to an Exchange mailbox, save it to the file system and delete the message in the mailbox. The other task of the application is to create a new message, let the user interact with the message content (add or delete text) and send the message. Preferably with the user interface of Outlook.

Answer:

You may choose either — both POP3 and IMAP are valid possible choices.  There are some factors that may guide you one way or the other:

1. Your Exchange Server administrator may have disabled POP3 or IMAP, so  you may be forced to choose a specific protocol if one of the protocols is disabled on the server.
2. If users are accessing the same mailbox in Outlook, then make sure they are not downloading and deleting the email from the server.  This would prevent your program from reading the email on the server if Outlook already removed the email from the server.
3. With POP3, the only way to create a new email on the server is to send email (via SMTP) to the mailbox.  With IMAP, you may create a new email and append it to the mailbox via the Chilkat.Imap.AppendMail or AppendMime methods.
4. The IMAP protocol does not allow for an existing email stored on the server to be modified.  To “modify” an email, you’ll need to fetch it, modify it, upload the modified email (which will now be a new email with a new UID), and then delete the old.