- # outgoing relay. Recipient verification is omitted here, because in many
- # cases the clients are dumb MUAs that don't cope well with SMTP error
- # responses. If you are actually relaying out from MTAs, you should probably
- # add recipient verification here. Note that, by putting this test before
- # any DNS black list checks, you will always accept from these hosts, even
- # if they end up on a black list. The assumption is that they are your
- # friends, and if they get onto a black list, it is a mistake.
+ # outgoing relay. It is assumed that such hosts are most likely to be MUAs,
+ # so we set control=submission to make Exim treat the message as a
+ # submission. It will fix up various errors in the message, for example, the
+ # lack of a Date: header line. If you are actually relaying out out from
+ # MTAs, you may want to disable this. If you are handling both relaying from
+ # MTAs and submissions from MUAs you should probably split them into two
+ # lists, and handle them differently.
+
+ # Recipient verification is omitted here, because in many cases the clients
+ # are dumb MUAs that don't cope well with SMTP error responses. If you are
+ # actually relaying out from MTAs, you should probably add recipient
+ # verification here.
+
+ # Note that, by putting this test before any DNS black list checks, you will
+ # always accept from these hosts, even if they end up on a black list. The
+ # assumption is that they are your friends, and if they get onto a black
+ # list, it is a mistake.