AirBNB style email masking service implementation with AWS Lambda

Question

I am building a small service application where users can cloak their email addresses using the service. Users who register to the website will have a unique email address to communicate with. I have tried to implement this relay service but i am stuck implementing it.

What i have tried

• Catch all the emails coming for the domain with SES receiving rules and saving to the s3 bucket
• Trigger lambda function to retrieve the original address of the designated user by calling an api call providing the email address user wanted to contact.
• After a successful call the api call returns the original (unmasked) email address for lambda to forward the email to

Question: Is this an overkill when dealing with 1000s of emails handled like this ? Is there any way that you had implemented such as this ?

*AirBnB style communication