I am getting a message "error occurred, constraint failed" when I try to receive mail.

I recently installed eMclient and it worked for a while and then a couple of days ago I started getting a message “error occurred, constraint failed” when I try to receive mail. Any suggestions as to how to fix this?

Hi Laura.

If it’s an IMAP account, please try removing that account which has this kind of problems and re-configure it in Menu > Tools > Accounts > Add account.

Russel