Mail app fail to connect to mail servers

The mail app can not connect to any private mail server neither public or private! same settings are done to a lot of mail servers created in a private network that works well with thunderbird and can not connect with the mail app in Nextcloud. Also in public mail servers. The settings are StartTLS and normal password with SMTP and IMAP, normal setting works with thunderbird.
Best Regards.

As mail server I had installed the following mail servers:

  • Univention Mail server

  • iRedmail

  • Zimbra

  • Postfix / Dovecot

  • Mail-in-a-Box

  • Modoboa

All the mail servers works great using the installed mail client while installing the server, like Sogo, Horde or Roundcube.

Using Thunderbird as mail client application also works very well.
Lastely I use the mail server inside univention corporate server and when i would like to connect using Nextcloud Mail app, it reply with the following error “Unexpected error during account creation” and could not connect to the mail server.

In another hand when trying thunderbird it connect well but and the fisrt send or receiving mail a window appear to get certificate and permanetly store the exception and confirm security exception, after this I could send and receive mail normally1 2 .

You might want to disable TLS verification in that case. See

FYI the ! in your text make the report sound rather rude. Please keep the feedback constructive.

Sorry for the ! sign I removed it and it was not meant as rudeness, sorry again.
Best Regards.

1 Like

What is in your opinion the best local mail server to integrate with nextcloud mail client?

PS: I use now the univention mail server, but there is a problem in the inbox it does not show the sent mails in both nextcloud mail client and thunderbird.