SSL with ZeroSSL.com

Ok. Now i have a certificate manually installed in the admin panel. I see in two of my 5 domains this text.

Signed & valid. The certificate expires in 89 days on 01/22/19.

If i enter to the webpage i don’t see error and the certificate is valid.

But if I use imap the error remains. The imap server is one that i renew the certificate. have I to put the certificate in another place?