for a workarround see https://sogo.nu/bugs/view.php?id=5124#c14680

also this is a duplicate report of 0005124 i guess

There are many errores after that:

root@mail:/home/comail# apt-get remove sogo
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package 'sogo' is not installed, so not removed
You might want to run 'apt --fix-broken install' to correct these.
The following packages have unmet dependencies:
libsbjson2.3 : Depends: gnustep-base-runtime (>= 1.26.0) but 1.25.1-2ubuntu3 is to be installed
Depends: libgnustep-base1.26 (>= 1.26.0) but it is not installable
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).
root@mail:/home/comail# wget http://packages.inverse.ca/SOGo/nightly/5/ubuntu/pool/focal/s/sope/libsbjson2.3_4.9.r1664.20200806_amd64.deb
--2020-08-12 10:26:29-- http://packages.inverse.ca/SOGo/nightly/5/ubuntu/pool/focal/s/sope/libsbjson2.3_4.9.r1664.20200806_amd64.deb
Resolving packages.inverse.ca (packages.inverse.ca)... 192.95.20.194, 2607:5300:201:2000::11:1681
Connecting to packages.inverse.ca (packages.inverse.ca)|192.95.20.194|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 14196 (14K) [application/x-debian-package]
Saving to: ‘libsbjson2.3_4.9.r1664.20200806_amd64.deb.1’

libsbjson2.3_4.9.r1 100%[===================>] 13.86K --.-KB/s in 0.1s

2020-08-12 10:26:30 (108 KB/s) - ‘libsbjson2.3_4.9.r1664.20200806_amd64.deb.1’ saved [14196/14196]

root@mail:/home/comail# apt-get install libgnustep-base1.26
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package libgnustep-base1.26 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'libgnustep-base1.26' has no installation candidate
root@mail:/home/comail# dpkg -i libsbjson2.3_4.9.r1664.20200806_amd64.deb
(Reading database ... 153986 files and directories currently installed.)
Preparing to unpack libsbjson2.3_4.9.r1664.20200806_amd64.deb ...
Unpacking libsbjson2.3 (4.9.r1664.20200806) over (4.9.r1664.20200806) ...
dpkg: dependency problems prevent configuration of libsbjson2.3:
libsbjson2.3 depends on gnustep-base-runtime (>= 1.26.0); however:
Version of gnustep-base-runtime on system is 1.25.1-2ubuntu3.
libsbjson2.3 depends on libgnustep-base1.26 (>= 1.26.0); however:
Package libgnustep-base1.26 is not installed.

dpkg: error processing package libsbjson2.3 (--install):
dependency problems - leaving unconfigured
Processing triggers for libc-bin (2.27-3ubuntu1.2) ...
Errors were encountered while processing:
libsbjson2.3
root@mail:/home/comail# apt-get install sogo
Reading package lists... Done
Building dependency tree
Reading state information... Done
You might want to run 'apt --fix-broken install' to correct these.
The following packages have unmet dependencies:
libsbjson2.3 : Depends: gnustep-base-runtime (>= 1.26.0) but 1.25.1-2ubuntu3 is to be installed
Depends: libgnustep-base1.26 (>= 1.26.0) but it is not installable
sogo : Depends: liblasso3 (>= 2.3.5) but it is not going to be installed
Depends: liboath0 (>= 1.12.0) but it is not going to be installed
Depends: libzip4 (>= 1.0) but it is not going to be installed
Depends: gnustep-make but it is not going to be installed
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).
root@mail:/home/comail#

Right now I have successfully installed SOGO but I can't log in - Wrong username or password. What I need to do?? Pls help!

fix your config i guess ;-)

the log files very likely contain hints whats wrong:

/var/log/sogo/sogo.log

or

/var/log/apache2/*.log

Broken config.

sogo.conf ?