Since you ask that general, assume you have this (pseudo code):
[pre]foreach(item in items) sendmail(item);[/pre]
If you don't want to send a mail per item, then the simple solution is not to do it in the loop, but after the loop.
[pre]foreach(item in items) addtomailbody(item);
sendmail(mailbody);[/pre]
So you have to define a variable for the mailbody, in which you add line for line, paragraph for paragraph, and finally just send this whole text once.
If you have such a problem with simple program flow, you shouldn't do programming. Seriously.
Bye, Olaf.