Lookup values in other lists

[Anonymous]

Can you run a program to check for values in other existing lists prior to sending emails. For examples, I have leads coming in via one program but I wanted to check if a specific lead value exits in a different list before executing an email.

Anyone has ideas on how to do this?

Thanks

[Josh_Hill13]

Yes you can do this and there are several ways, depending on the exact nature of your flows:

1. If your campaign is based on Campaign IS REquested, then just add filters below the trigger to block the group.
2. Flow: use Choice steps to check for a Value or Membership before sending. This is less desirable because it should have blocked those people at the Smart List. Best used when you have several options to send.
3. Check in Requesting Campaign - use a Choice Step
4. Use a traffic cop (don't hate me!) - this checks for data value changes and routes the lead appropriately.

[Anonymous]

I think my question was a bit misleading. I am trying to check if a particular value is present in another list with any of its members. So for example, 

IF Lead Value X is present in List A - then DO NOT send email
IF Lead value X is not present in List A - then do send email and add to list A

Does that make more sense?

Thanks for the answer - It will be useful for other projects.