Emails not being sent (stored in the outbox of Local folders)

Recently, I have had issues when sending emails from the email account of one of my clients. This is an account set up in Outlook, and I don’t know why, when I try to send an email, it appears in the “Outbox” of the Local folder, but it is never sent. 

I have been using EM with this account for more than a year and never had this issue before. I have asked my client and they say they haven’t changed anything at their end.

Any ideas?

No psychics on this forum Alexandre. ;-)  How about the an error message?

In the mean-time, disable anti-virus and firewall application and see if that changes anything, or if eM Client was recently updated, uninstall and then reinstall the previous version.

I wish I had an error message! But I get none! :( 

However, uninstalling and installing again did work, so thank you for the advice!!!