Yes, you can have several conditions in your Exclusion Script with the only main rule that it should end up with 'True'
or 'False'
result. In your case, it would look somewhat like that -
(ROWCOUNT(LOOKUPROWS("Data_Extension_1", "EmailAddress", emailaddr)) > 0
AND
ROWCOUNT(LOOKUPROWS("Data_Extension_2", "EmailAddress", emailaddr)) == 0)
OR
(ROWCOUNT(LOOKUPROWS("Data_Extension_1", "EmailAddress", emailaddr)) == 0
AND
ROWCOUNT(LOOKUPROWS("Data_Extension_2", "EmailAddress", emailaddr)) > 0)
Lastly, before creating a condition, review the LookupRows AMPscript function guideline to create correct filtering criteria.
And check out answers to those questions:
- Exclusion Script
- Inverse exclusion script
- Exclusion Script with time
Hope it helps.