If you are only interested in pulling out the SMTP email address from the field, you could get it to work this way:

# ... up to this point, 
# you must have read 1 line from the file ...
# and (for sake of example) the email field saved in into $email_field
+ variable.
my @emails;
while ($email_field =~ m/SMTP:([^\%]+)\%/g) {
  # validate matched email first... (as per UPDATE)

  push @emails, $1; # add email address to the list
}
# @emails array now contains all SMTP email addresses
# found in the field.
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Here, I look for any sub-string in the field bounded with string 'SMTP' on the left and '%' character on the right. Option /g allows regular expression to pick successive occurances of a matched string (on every loop cycle). You could read more on this and many other features of Perl regular expressions here.

UPDATE: thanks jeffa. The reason I used the while loop is to also possibly include some email address validation inside the loop for every match. Therefore, only 'correct' email addresses would go in the array. Of course, a one-liner would work better if no such thing was required or validation occurred later on the @emails array.

_____________________

$"=q;grep;;$,=q"grep";for(`find . -name ".saves*~"`){s;$/;;;/(.*-(\d+)
+-.*)$/;$_=&#91"ps -e -o pid | "," $2 | "," -v "," "]`@$_`?{print"
++ $1"}:{print"- $1"}&&`rm $1`;print"\n";}
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