Serial number error for version 2.9.50

Hi, I just purchased SpamSieve 2.9.50, for Mac OS 10.12.6 and I’m getting this error message. "Sorry, but that’s not a valid license for SpamSieve 2.9.50.” My email purchase confirmation says SpamSieve 3.0.3 (1-user license) How can I get a license for 2.9?

(I use Airmail version 3.6.71)

Purchasing the latest version of SpamSieve entitles you to a license for older versions of SpamSieve, which support older macOS versions. I will send you the SpamSieve 2.9.50 license via e-mail.

Great. Thank you!