[imp] How to specify HELO address ??

[Nigel Cass]

Hi All.
I am now trying to set imp to send mail using SMTP rather than using
sendmail.

It is quite straightforward and does exactly as it should.

However according to the mailhub I am sending via, the imp server
advertises itself as localhost when it performs an SMTP HELO rather than
it's name.

Which option do I have to set to force the correct DNS name to be
advertised in the SMTP conversation ?

TYIA

Nigel Cass.