Hi, I'm currently developing a scrambler plugin which should be used to store the mails encrypted on the disk. It uses a special ostream for encryption and an istream for decryption. The idea is, that if a mail arrives via LMTP it goes through the ostream and is written encrypted to disk. If an mail is accessed via IMAP, the istream is used to decrypt the data from disk. That all works fine, but if I add the zlib plugin it all gets mixed up. For some reason, the lmtp process tries to read something from disk using the chain of istreams. That behaviour is a little bit bizzare to me, because my understanding is, that the zlib plugin at this point should only write (compressed) data to disk. Why is the istream used here? And what is read? If I remove zlib from the configuration again, it all works as expected. The dovecot version is 2.1.17. Best regards, Philipp