Basically the title:
I have a large amount of records in Salesforce that I need to check and see if they exist in marketo. Is there a way to do a lookup on a large number of records (preferably looking at just the email address since that is what matters most) to see if they exit in Marketo?
Any advice would be appreciated.
Option 2:
Import your list, any amount lines.
Choose at beginning of the import process "Skip new people and updates"
What is "large"?
a bit over 9,000
That's not large.
For a list that small, cut it into blocks of 1000 to be on the safe side, then paste each block into a Smart List filter on Email Address (multi-choice box).