We have developed a report distribution system that includes the ability to e-mail attachments that appear to be in Excel format to the recipient, simply by sending a tab delimited file with the .xls extension. Users have requested that e-mail attachments be password protected. Obviously, this won't work with the tab-delimited file, but is there a way this can be done -- integration with Microsoft Excel? Perhaps a third party product that you know of?
You could use OLE to integrate SAP with Excel - create files, execute macros etc. (search for DOI on SAP help), but this will only work on the presentation server, so you couldn't run it as a service in background. I suppose your e-mails are sent through the internet, hence the requirement for encryption -- or maybe your client doesn't trust its network people! For this you really should use strong encryption -- anything less, you might as well send plain text. One solution to this would be to send the email down a VPDN -- this would encrypt all traffic between source and destination. Another would be to encrypt the file just before it is attached to the email. This could be done within ABAP, but perhaps a third party public key encryptor would be better placed. This could be invoked via a system command call, or as an RFC. A third solution would be to have your mail server handle the encryption.