To further address this issue, please contact your mail provider and ask them for the following details:
1. IMAP and SMTP mail server addresses.
2. Port numbers for the IMAP and SMTP mail servers.
3. Do you need to authenticate when sending mail?
4. Do you need to use SSL?
Verify with them that the username and password that you are using are correct.
In the top menu of the main IncrediMail window, click on Tools > Email Accounts, select the particular account and click on "Properties".
Check that the details you have in IncrediMail are indeed correct.
To learn more about changing your email account settings, please refer to our online article at:https://incredimail.zendesk.com/entries ... il-account