When attempting a doveadm backup, e.g. :

doveadm -D backup -Ru user tcp:foo.example.com:12345

I am getting the following error :

Error: SSL handshake failed: SSL_accept() failed: error:0A00010B:SSL routines::wrong version number

There is nothing wrong with my SSL config because, e.g. openssl s_client -connect localhost:993 works on the source host.

So I don't know why doveadm doesn't work.

My SSL config is: ssl = required ssl_cert =