Authentication-Results header wrapped at 76 columns

Products

• Messaging Gateway

Issue/Introduction

When constructing the Authentication-Results header, Messaging Gateway will wrap the header data at 76 columns for long sender addresses if no whitespace is available before 76 characters to wrap the header. This causes the sender address in the header to be split across multiple header lines.

Example:

Authentication-Results: symauth.service.identifier; dmarc=pass (p=none,
               dis=none) header.from=host.example.com; senderid=pass; spf=pass
               smtp.mailfrom=[email protected]
               .com smtp.helo=mta.relay.example.com;
               dkim=pass header.d=mta.relay.example.com header.s=200608
               [email protected] header.v=1
               header.a=rsa-sha256

Resolution

This does not cause problems for the Messaging Gateway sender authentication features as the header is properly unwrapped for content analysis but may cause issues for downstream email security or auditing solutions which may not properly unwrap the header due to the unexpected break at 76 columns.

This issue will be addressed in a future release to align with standards for line wrapping of long message header content.