One of my users on VTEXT Android Samsung Intensity has this issue.
I was able to work around by forging a reply. I had the user send me the ACNID: information.
General Instructions for sending mail via a command line telnet sessions can be found here:
Telnet - SMTP Commands (sending mail using telnet)
After the data command I used--
Subject: RE: Alert Central Email Validation ${ACNID:2948}
hit enter
hit enter
validate
.
single period on line alone is important.
Note the ACNID was from the users validation request text.
User verified he received the validation confirmation.
This issue was going to be a show stopper.
Good Luck --
--Cindy