[exim] Exim4 using libsecret, secret-tool or keyring?

I have Exim4 running on my Ubuntu 20.10 server and have successfully got local mail and SMTP outgoing to a SmartHost working fine. Thus, I now have the host and password stored in /etc/exim4/passwd.client


Is it possible to get Exim4 to request this password from an encrypted source, such as libsecret's secret-tool or something else like password.store, in a similar way as msmtp can be configured to do.