I understood that imap.example.org and imap.example2.org are reachable from the Internet via the same IP, right ?
In that case just extend the certificate (probably with certbot) with the second domainname.
yours sincerely
Robert

Am 19. Februar 2018 03:41:18 MEZ schrieb Gabriel Kaufmann <mailings@typoworx.com>:

I've tried setting up multiple SSL-Certificates (using letsencrypt) for dovecot on my ubuntu machine. Used dovecot version is 2.2.18.

Regarding to official docs this should be working.

My test-client (Thunderbird on linux) has been mentioned to be working fine with SNI here:
https://wiki.dovecot.org/SSL/SNIClientSupport

https://wiki.dovecot.org/SSL/DovecotConfiguration#line-89

local_name imap.example.org {
  ssl_cert = </etc/ssl/certs/imap.example.org.crt
  ssl_key = </etc/ssl/private/imap.example.org.key
}
local_name imap.example2.org {
  ssl_cert = </etc/ssl/certs/imap.example2.org.crt
  ssl_key = </etc/ssl/private/imap.example2.org.key
}

Did anyone have success on this (without using multiple IP per Domain)?

-- 
Best regards

Gabriel Kaufmann

mit freundlichen Grüßen
Ing. Robert Nowotny
(von Mobile)