Cannot receive emails but can send. Server repeatedly asking for password which is unknown.
So, you don’t know the password? You need to contact your email provider. Who is your provider? Are you using POP3 or IMAP for receiving? Your provider may require a 2-step authorization.
If your problem is with outlook.com or hotmail.com microsoft made some changes and em client needed a fix. unfortunately em client put the info on their facebook page but not easy to find on emclient.com. Facebook page has link to fix. I downloaded and installed, when eMclient opened after fix, got request from Microsoft for my account password with a spot to actually enter the password, not like before fix where there was nowhere to enter password. Fix worked
I’ve had this issue… perhaps emclient needs an update?
davew - you say you HAD this issue. Did you get a solution?
Also, just had a thought. Windows 10 Version 1809 update has installed in the last few days. Could this be a relevant factor?
I simply uninstalled emclient… downloaded the latest from the download link… and seems to have fixed it
Im going to try next time to remove the account and readd it back… see if that helps… will keep you posted
If I uninstall will I lose all my emails to-date?
if its realted to a hotmail account…and your NOT USING POP… no… cause the mail is stored on hotmail.
just back up your local folders if your using them
as Lilibit01 said… its to do with outlook/hotmail making changes… not emclient as such
but emclient has had a fix
Problem solved. Provider gave me new password and 4 days of emails flooded in.
My thanks to those who responded to my problem. 
Call your email provider and have them change or tell you what the password is and than enter it when it asks for your password
Rather than delete the IMAP version of the Microsoft eMail addresses and change to exchange, I applied the ‘FIX VERSION’ (Windows in my case) which was listed on this post;
https://forum.emclient.com/emclient/topics/reaction-to-the-outlook-com-authentication-problem?fbclid…
And upon restart, I was prompted to enter my passwords into a new Authentication page, and all the emails were downloaded into eM Client for those accounts.
Looks fairly successful so far
I was suggesting you should make it available in the downloads section in the https://www.emclient.com/release-history poss make it easier people to find it?