====== SMTP data timeout (message abandoned) on connection from ======
Error "SMTP data timeout (message abandoned) on connection from" ini ada kemungkinan disebabkan setting  smtp_receive_timeout. 

Dokumentasi disini http://www.exim.org/exim-html-3.20/doc/html/spec_11.html

Di directadmin default smtp smtp_receive_timeout=5m bisa dilihat pada /etc/exim.variables.conf