e-mail was working fine then one day I can send e-mails but can’t receive them
Two things you can try:
Check your settings. Go to Menu > Accounts and click on the IMAP tab for your email account. Make sure the port is set to 993 and the security policy is Use SSL/TLS on special port (legacy). If you have a POP3 tab rather than an IMAP one, make sure the port is set to 995 and the security policy is Use SSL/TLS on special port (legacy). Restart eM Client and see what happens.
Disable any anti-virus/firewall or VPN and try again.
If neither helps, go to Menu > Operations and look for any IMAP or POP3 errors in the Log tab.