Hi all if you face errors with logging in to Rainloop and if your logs have something as "Invalid password in passdb: crypt() failed: Invalid argument" Then there is a simple fix for this. You need to update your Dovecot to 2.3.x as bcrypt is supported by 2.3.x. The steps are as follows:
1) Add the reposity key of dovecot to the rpm key store:
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 18A348AEED409DA1
2) Add the official dovecot Ubuntu Repo to sources.list
(this example is for Ubuntu 18)
sudo nano /etc/apt/sources.list.d/dovecot.list
deb [arch=amd64] https://repo.dovecot.org/ce-2.3-latest/ubuntu/bionic bionic main
Save it and close editor
3) Do a:
sudo apt update
4) Do a:
sudo apt dist-upgrade
5) Reboot your machine.
you rainloop should work nicely now.
Original post - https://forums.cyberpanel.net/discussion/5385/workaround-for-some-problems-can-t-login-in-rainloop