==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.6.1
- Deployed with iRedMail Easy or the downloadable installer? Installer
- Linux/BSD distribution name and version: Ubuntu 20.04.5 LTS
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx): Apache
- Manage mail accounts with iRedAdmin-Pro? No
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

Hello,

doing the upgrade from 1.6.0 to 1.6.1 I have changed the /etc/apt/sources.list.d/sogo-nightly.list an described.
When I run apt-get update I get the following message:

The repository "xxxxx://packages.sogo.nu focal Release" does not contain a release file.
N: Updating from such a repository cannot be done in a safe way, so it is disabled by default.
N: See the apt-secure(8) man page for more details on creating repository packages and configuring them for users.

Any suggestions are very welcome

regards, Harald