best attr for multiple fields in one TAB-separated field ..

To: openldap-technical@openldap.org
Subject: best attr for multiple fields in one TAB-separated field ..
From: lejeczek <peljasz@yahoo.co.uk>
Date: Thu, 18 Jun 2015 17:49:06 +0100
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User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0

.. which would be mail related, can somebody recommend?
many thanks.
P.