Bare carriage returns and bare linefeeds are technically not allowed in e-mail messages.


This article applies to:

  • Trustwave MailMarshal (SEG)

Symptoms:

  • Bare carriage returns and bare linefeeds are technically not allowed in e-mail messages.
  • Some e-mail systems create messages containing bare carriage returns or bare linefeeds.

Resolution:

In current versions, you can configure MailMarshal to block, fix or ignore messages with bare carriage returns and/or linefeeds.
  1. Edit advanced properties of the Receiver
    • MailMarshal (SEG) 10 Management Interface: System Configuration > Array Properties > Receiver > Advanced
    • SEG 7.X and 8.X: MailMarshal Configurator: Trustwave SEG Properties > Receiver > Advanced
    • For earlier versions, see the documentation to find the location
  2. In the Bare Carriage Returns drop-down box, choose the desired behavior:
    • Block: Messages containing bare CRs will be dead-lettered
    • Fix: Bare CRs will be converted to CRLF
    • Ignore: Bare CRs will be passed though unchanged (this is the default behavior)
  3. In the Bare Linefeeds drop-down box, choose the desired behavior:
    • Block: Messages containing bare LFs will be deadlettered
    • Fix: Bare LFs will be converted to CRLF
    • Ignore: Bare LFs will be passed though unchanged (this is the default behavior)

 

Notes:

A bare carriage return is the 'CR' (carriage return) character without an accompanying 'LF' (linefeed).

A bare linefeed is an 'LF' (linefeed) without a preceding 'CR' (carriage return).

This article was previously published as:
NETIQKB29671
Marshal KB488

Last Modified 4/1/2020.
https://support.trustwave.com/kb/KnowledgebaseArticle10016.aspx