I found this 6 - Self-signed SSL error on Outlook/Thunderbird - 06 - Email - CyberPanel Community
And this is what is in my dovecot.conf
I notice mail.mail for the 2nd domain even though the child is mail.domain2.com
I also notice that the ending slug for domain2 and domain3 are different from domain1 and all are different from what’s in the doc
/fullcm, /privkem vs /fulm, /privem vs /m or no slug
vs
/privkey.pem and /fullchain.pem (doc)
?