$ swaks --pipe 'exim -bh 8.8.8.8' -f … -t info@example.org,office@example.org -q rcpt
<-  
<-  **** SMTP testing session as if from host 8.8.8.8
<-  **** but without any ident (RFC 1413) callback.
<-  **** This is not for real!
<-  
<-  220 jumper.Speedport_W_724V_Typ_A_05011602_00_001 ESMTP Exim 4.80 Sun, 11 May 2014 15:16:37 +0200
 -> EHLO jumper.schlittermann.de
<-  250-jumper.Speedport_W_724V_Typ_A_05011602_00_001 Hello jumper.schlittermann.de [8.8.8.8]
<-  250-SIZE 52428800
<-  250-8BITMIME
<-  250-PIPELINING
<-  250 HELP
 -> MAIL FROM:<hs@schlittermann.de>
<-  250 OK
 -> RCPT TO:<info@example.org>
<-  250 Accepted
 -> RCPT TO:<office@example.com>
<** 451 multiple recipients for differend domains
 -> QUIT
<-  221 jumper.Speedport_W_724V_Typ_A_05011602_00_001 closing connection
