RFC-Compliant Base64 Encoding in Domino SMTP

Customers using XPages-based applications face email delivery failures with strict mail servers (e.g., GMX) due to RFC 5322/2822 violations (“500/501 line too long”). The issue occurs when inline images are converted into MIME parts encoded with Base64, where Domino SMTP sends the encoded data as a single long line instead of inserting RFC-compliant line breaks. While manual line-breaking resolves the issue, it causes encoding problems in other MIME parts (e.g., text/html and special characters). There is currently no supported programmatic solution to address this behavior. We request an enhancement in Domino SMTP to automatically format Base64-encoded MIME content in an RFC-compliant manner. If possible, a configurable option (e.g., notes.ini parameter) should be provided to control this behavior. This will improve email interoperability and reduce the need for custom workarounds.