[horde] changing from address

[Brian Clifton]

When sending a message Horde shows, From: user1 at domain.tld

How can I change this to user2@ without changing the login name?
This is the a default catch-all account so I don't want to add an 
extra mailbox - just change the From: name

Best regards, Brian

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Omega Digital Media Ltd

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Phone: +44 (0)1444 410 202
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http://www.omegadm.co.uk
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