{{Silently delete mail to the user at the current domain.}}
val defaultAlias = \email -> aliasPrim defaultSource (addressTarget email);
+{{When a message to the current domain doesn't match any other alias and isn't a
+ UNIX username, send it to this e-mail address.}}
+val catchAllAlias = \email -> aliasPrim catchAllSource (addressTarget email);
{{When a message to the current domain doesn't match any other alias, send it to
this e-mail address.}}