Prior to Domino R5, the R4.x SMTP MTA handled messages that contain HTML code by placing the HTML code into an attachment with a file name called ATT1.HTM. The end result was the R4.x user could launch the attachment because the HTM extension is associated with the default web browser, the HTML code could be displayed, and all URLs could be retrieved.
Since R5 clients can send and receive in HTML, however, it is possible to have a network constraint. An example of this constraint is requiring username and password for internet access because the client is not able to connect to web sites with the Notes client it cannot retrieve the HREF URLs referenced in the HTML code. Since the client cannot connect to the URL needed, this results in an empty image with a red 'X' in the upper left-hand corner of the image.
Solution
This issue was reported to Lotus Quality Engineering and has been addressed in Domino 5.0.7 with the addition of the following NOTES.INI parameter:
MIME_CONVERT_HTML_TO_ATTACHMENT=1
This NOTES.INI parameter makes the R5 server act like the R4.x SMTP MTA -- all body parts containing HTML code are moved to attachments, and when end users launch the attachments, it launches the default web browser.
Note:
This requires all users' Person document's "Format preference for incoming mail" field be set to "Prefers Notes Rich Text" and the server performing the conversion process to be running R5.0.7. Since upgrading all users' mail servers to R5.0.7 takes time, it is possible to force the message conversion on the 5.0.7 SMTP servers by running the "MailConvertMimeOnTransfer=1" NOTES.INI parameter. Depending on the volume of mail being received, this parameter could cause performance problems.Supporting Information:
MailConvertMIMEonTransfer
Syntax: MailConvertMIMEonTransfer=value
Description: Enables or disables the router to perform conversions for MIME messages. This can help minimize conversion overhead on the server running the SMTP listener task:
0 - Router does not perform conversions for MIME messages
1 - Router performs conversions for MIME messages
MOD