Open the Settings page
Click the Cog Button in the upper right corner. Select to the Settings entry from the drop down menu.
Open the POP3 account settings
Select the Accounts Tab of the setting page. In the Check email from other accounts (using POP3): section select your account and click on edit info behind this account.
Re-enter the Password for this account, set the POP Server Port to 995 and activate Always use a secure connection (SSL) when retrieving mail. Save the settings by clicking to Save Changes >>.