Would love some suggestions on how to handle this. Each email we send is associated with a unique key code made up of a (mostly unintelligible) string of letters and numbers that is different from the Marketo program ID. This key code is used in Marketo but its also used in some of the other systems we use. We have been using that key code as part of the program name but those names get long and messy and we'd rather just use something simpler like the recommended "ES-YYYYMMDD-(program name)" format.
Is there a way to add a custom identifier to an email send that would show up as a column in reporting?