A SNS topic has 2 subscriptions. one with filter policy (lets call this A) and other without (lets call this B). When a message is published to the SNS topic with filter attributes matching subscription with filter policy(subscription A), it receives the message. The issue I am finding here is the one without filter policy(subscription B) is also receiving the same message. How do I send message to only subscription "A"?
Say I add a different filter policy to subscription B. Then if I publish message to SNS with filter policy attribute of subscription A, only the subscription A will receive the message. This solves the problem I mentioned earlier, but there is a limit of 200 subscription filter policies per account. This kinda destroys the purpose of having subscription filter policies.
To conclude my question : How do I send message to only subscription "A" without adding filter policies to other subscriptions of the same topic?
NOTE: The SNS protocol used is EMAIL. I am also NOT looking into increasing the SNS limit.
If your use-case is to email users, then Amazon SNS is not really an appropriate architecture. Amazon SNS is best used for message-passing between applications, or for alerts to internal staff.
For emailing external users, you really should use Amazon Simple Email Service (SES).