[exim] Failed to expand ACL string

Hello,

Using Exim 4.74, in the ACL checking the sender address I have the
following snippet:

  accept  senders = :
  deny    set acl_m_spf_dns = ${lookup dnsdb {>\n; txt=           
                                 $sender_address_domain}}

(The above 'deny' is all one line.) However in my log file I am getting
error messages about this. For example:

    2011-02-07 11:37:15 H=(mail.aston.ro) [95.64.115.74]:35564
    temporarily rejected MAIL <alert@???>: failed to
    expand ACL string "${lookup dnsdb {>\n; txt=
       $sender_address_domain}}": lookup of ">

From the docs, the use of '>\n;' seems to be correct, so I am a little
unsure what the problem is. Anyone any ideas?



Thanks,

John.

-- 
John Horne                   Tel: +44 (0)1752 587287
University of Plymouth, UK   Fax: +44 (0)1752 587001