I've asked this before and thought I had resolved but the problem still occurs!
A user is emailing a particular domain and getting the following error:
riverexch.riverltd.co.uk #5.5.0 smtp;550 Sorry, your HELO/EHLO greeting must resolve (#5.7.1)
Under SMTP VS Properties the FQDN is set to riverexch.riverltd.co.uk but the Masquerade domain field is blank...could I put something in here to resolve i.e our email domain which is therivergroup.co.uk??