Since the new Debian Buster update, I have some issue with TLSv1.3.

Issue: my iOS mail client could not connect to my mail server (12.2) and I do not want to upgrade right now, so I try to find a way to disable TLSv1.3 with dovecot.

The current versions are: OpenSSL 1.1.1c and Dovecot 2.3.4.1

In Dovecot 2.3 the SSL settings are changed from ssl\_protocols to ssl\_min\_protocol.

```
# Minimum SSL protocol version to use. Potentially recognized values are SSLv3,
# TLSv1, TLSv1.1, and TLSv1.2, depending on the OpenSSL version used.

```

But I would like to force Dovecot to use TLSv1.2 instead of using a minumum SSL protocol, because Dovecot will try before the highest SSL protocol available first (TLSv1.3). If I set TLSv1.3 it will not use TLSv1.2.

So, anyone known how to force Dovecot 2.3.4.1 to use TLSv1.2?