[Exim] Any identify this MTA?

Does anyone know which MTA prints out a bunch of asterisks and junk
as its initial greeting? e.g.:

220 ***************2**********************2*0*0 ***

Under exim 3.36, I'm having issues delivering to a few domains
whose only initial greeting is the above (or a variation of that).
Basically, I get:

"Connection timed out: SMTP timeout while connected to x [x] after end
of data (x bytes written)"

This seems to only happen to MTAs that output the junk greeting. Debug
doesn't give any pointers except for the timeout.

Any clues appreciated.

Paul