Dave Crocker wrote:
We need *some* term, so that such references as "boundary
MTA" can be meaningful -- what is it the boundary of?
Keith proposed MON (mail originating network) and MRN
(receiving). If you want to talk about "boundaries" the
direction can be important - not necessarily, maybe one
term is eough for your purposes. On the receiving side
MX could be good enough as term for most "boundary MTAs".
If that's also the case for your text you'd need only a
term for "RMX" like "mailout" (?) In your image the five
MTAs at the bottom would then be (LTR) MO, MX, MX, MO, MX.
In your 6th AE you have a "mediator" on top of MDA / MSA.
IIRC that used to be a special case ("gateway") in -03 of
mail-arch. The critical cases were mediators in the blue
Trying to interpret the picture as is, for the connection
of the 2nd (left) AE with the 5th (middle) AE I'm not sure
why it passes _through_ the 3rd AE without MTA. Is that
connection meant to be independent of the 3rd AE, should
it in fact bypass (line below the blue zone) the 3rd AE ?