This is the code I´m using, taked from some examples of your site, just to build a little test before set the entire application:

SET CLASSLIB TO wwIPSTUFF ADDITIVE
SET PROCEDURE TO wwUtils ADDITIVE
o = CREATEOBJECT("wwIPStuff")

o.cMailServer = "mail.megared.net.mx"
o.cSenderEmail = "prueba@cci.com.mx"
o.cSenderName = "Adrián Hernández"
o.cRecipient = "obsenum@hotmail.com"
o.cSubject = "Un correo de Prueba"
o.cMessage = "Hola...." &&cfg1.mail_cont
o.cContentType = "text/html"

llResult = o.SendMail()       
IF !llResult
   Wait window o.cErrorMsg
ENDIF

mail.megared.net.mx is my IPS and has no restrictions. I even try with "148.233.132.33" and "148.233.132.34" both are mail servers of the company. In any case I receive a "501 5.0.0. Invalid domain name" message... Am I doing something wrong? Thanks in advance, Rick!