Cheers all, got question (could n`t find it anywhere) for IMAP;
Namely, thing is I get users running outlook (Thunderbird as well) getting these Certificate expired issues. All they can do is click Yes (Install, Accept, Yes) and all goes away. Mail client acts as nothing is wrong. Then I took a stroll trough Plesk admin and (there I have a module installed which enables me to renew mail cert) and I see that certificate shows as valid for another three months. Now...I can`t seem to find the expired certificate. My knowledge has made me to conclusion that it`s not postfix problem, rather Dovecot (as he is acting as an IMAP server, if my understanding is correct). Now, what bothers me is that, even tho this should prove to be a "piece of cake" for someone who has understanding of this - to me it is not. Not ye...hopefully one day. Does anyone has any advice? My idea is (if I`m correct), just use openssl to generate that friggin .pem file and place it wheer it should be, matching the path (or other way around). Help! And yes, mock me..I have spent couple of days browsing for solutions and that only fattened the possible solutions.

Thank you all in advance;

peace.

In my case I have both postfix and dovecot certs created and installed. Certificates are from using certbot, and are renewed every 90 days.

In my dovecot.conf file I have

ssl_cert = </path/to/fullchain.pem
ssl_key = </path/to/privkey.pem

Obviously those two files exist.

In my postfix main.cf file I have the following configuration items.

smtpd_tls_cert_file = /path/to/fullchain.pem
smtpd_tls_key_file = /path/to/privkey.pem

Again, both these files exist and were created with certbot.

Both the dovecot and postfix certs are different (although the example above makes it look like they are the same. my actual paths are different).

Hopefully that helps?

Founded this:
--L_accept() failed: error:14094416:SSL routines:SSL3_READ_BYTES:sslv3 alert certificate unknown: SSL alert number 46, session--

But no obvious config missmatch. I`ll guess I just have to keep digging....