Email Mapping to Meta Destination

Hi ​@DavidRoss91,

This is very likely a contributing factor, though it’s worth being precise about the mechanism, it’s not really a collision, it’s an overwrite. Field mapping in destinations is 1:1 per target field, so when two different source fields both map to the same single-cardinality target (email), whichever one gets evaluated last simply overwrites the other during export. Nothing errors out, so you won’t see it in logs, you’ll just quietly lose signal for any profile where those two source fields hold different values.

That’s worth flagging specifically for Meta, since their Custom Audience matching can actually use multiple email identifiers per user to improve match probability. If the intent was to give Meta both emails to maximize matching, the current mapping works against that, since only one ever makes it through.

The fix depends on what those two fields represent. If they’re genuinely different emails you want both sent, they need to go into an array-typed target field rather than both pointing at one scalar, assuming Meta’s schema supports a list for email identifiers. If one is meant as a fallback when the other is null, you want coalesce-style logic in the mapping rather than two direct mappings racing each other.

To confirm this is actually your root cause before changing anything: pull a sample of profiles where the two source email fields differ, and check what landed in the actual destination export for those profiles. If it’s consistently only one of the two values coming through, that’s your overwrite behavior, not a hashing or normalization issue elsewhere in the pipeline.

Hi ​@akhil_merupula ive thought of the coalesce type mapping logic as well, but the facebook destination does not give the option for calculated attributes within the mapping set 

We’ve been able to accomplish this using our cdp prior to implementation of Adobe ecosystem. So it does seem the first thought regarding overwriting of attribute plays to where the issue is