#followerpower #question #email #sieve #filtering

I'm trying to write a server side filter script for emails with sieve.

Setting:

I'm planning to publish a very basic newsletter; no fancy A/B shit or CRM foo.
Mails, subscribers etc. are managed via Thunderbird.

Registration is semi-automatic as follows:

1. User sends an empty registration email with subject "registration" to newsletter@domain.xyz.
2. Server-side Sieve script recognises the subject and autoresponds with "THX and confirm with code xyz."
3. User sends an empty acknowledge email with subject "xyz" to newsletter@domain.xyz.
4. Sieve script recognises the subject's code and autoresponds with "THX and have fun!"

Assigning the user's mail address to the distribution list happens manually.
I don't expect thousands of subscribers, so this will do for now.

Is it possible to generate some kind of (md5) hash from the senders address (or other unique mail data) with sieve so the first autoresponder mail contains this hash and sieve is able to verify this hash with the subject of the acknowledge mail?

Any help or idea is appreciated.