substr

Returns a part of the string – e.g. first 10 characters of message subject:

${MessageSubject.Substring(0, 10)}

Note that you should be aware of the fact that sometimes variables can have different length and you should always make sure that your statements are always valid – in the example below we’re writing the first 1000 characters of the MessageSubject variable or the whole MessageSubject variable – depending which is less. If we didn’t have that condition than the DC system would report an error for MessageSubject variables having less than 1000 characters – because it is not possible to show 1000 characters when the variable has less than that.

${MessageSubject.Substring(0, System.Math.Min(1000, MessageSubject.Length))}