SurgeMail can redirect mail in one of four ways. These can be mixed but we suggest you pick one and use it as it can get very confusing:
Global redirection takes place as soon as the message arrives and is applied to local and non local addresses. Global redirection rules should use fully specified email addresses.
g_redirect was="user1@fulldomain" to="user2@somedomain"
This is powerful but means you can unwittingly redirect outgoing mail. eg: redirection of postmaster@* -> admin@mydomain will redirect incoming mail for postmaster accounts on all local domains to admin@mydomain BUT will also redirect outgoing mail for postmaster@remotedomain to admin@mydomain!
redirect was="user1" to="user or user@otherdomain"
Redirects under the same category will all be applied at the same time and multiple rules may be applied. Also redirection may be to accounts which are in turn being redirected.
Both local and global redirection allow * wildcard to be used in the "was" field and the %n wildcard to be used in the "to" field.
eg. *_*@domain -> %1@%2.domain
would allow joe_bloggs@domain to be redirected to email@example.com
The g_gateway setting is a final form of mail redirection that will will redirect mail for an entire domain (or subdomain) to a particular IP address.
Typically this other server is inside a fire wall so its local IP address is not known by the DNS server. You specify the domain and IP address (and optional login information) to send messages to and this server is treated as 'local' rather than remote in terms of open relay restrictions.