Dovecot dh

• /etc/dovecot/conf.d/10-ssl.conf

From and up to version 2.2

ssl_dh_parameters_length = 4096

From version 2.3, you must specify path to DH parameters file using

ssl_dh=</path/to/dh.pem

To generate new parameters file, you can use:

• openssl dhparam 4096 > dh.pem