How the system detects shared emails
Duplicate detection runs automatically in the background. The highest-priority rule it uses is an exact email match: if two contact records in your database share the same email address, the system flags them as a likely duplicate pair and surfaces them in Merge Duplicates.
Because email is the strongest duplicate signal, a shared email almost always means the two records belong to the same person and should be merged.
When to merge
If the same individual donated twice, was imported from two different spreadsheets, or signed up through a form while already in your database, you will end up with two separate records that share one email. In that case, merge the two records into one.
To do that:
Open the contact record for either person.
Click Merge Duplicates (or navigate to the Merge Duplicates section of your database).
Review the proposed match. The system shows you which fields each record holds.
Select which record to keep as the primary and confirm the merge.
After the merge, the surviving record keeps its own field values. Where the surviving record had a blank field and the removed record had a value, the value transfers over. All donations, pledges, notes, call history, tags, and list memberships from both records move to the surviving record. The removed record is then soft-deleted and will not appear in your database.
When to keep records separate
A small number of households share a single email address, typically a couple who use the same inbox. If you have confirmed that the two records are genuinely two different people, you can dismiss the duplicate suggestion and keep both records. They will remain linked in any email campaigns by that shared address, so only one of them will receive email at that address. Make sure you understand this before dismissing.
If you want to track the relationship between the two people, use the Related People feature on either profile to link them as household members.
Effect on email campaigns
When a campaign is finalized, the send list is built from contact records. If two records share an email address, both records are in the send list but the email address itself receives the message once per unique address, not once per record. Merging removes the duplicate entry and keeps your list cleaner.
Effect on ActBlue matching
When a donation arrives from ActBlue, the system matches it to a contact record using the donor's email address. If two records share that email, the donation attaches to whichever record the matching logic resolves to first. Merging the two records before or after the donation arrives ensures all giving history ends up on a single profile.