Please check to see if Thunderbird is blocked access to internet as no point checking anything else if this is blocked by your Firewall. Do not switch off Firewall - just get the program thunderbird.exe allowed. Exit Thunderbird now. Access Firewall (note it may be controlled by Anti-virus product) Thunderbird program must be set up as an allowed program. So if it is not currently set up as allowed then set it up. Start Thunderbird. Check imap setting for gmx * Incoming: imap.gmx.com * port: 993 * Connection Security: SSL/TLS * Authentication Method: Normal Password * User Name: full email address * Password - same one you use to access webmail account * Outgoing: mail.gmx.com * port: 587 * Connection Security: STARTTLS * Authentication Method: Normal Password * User Name: full email address * Password - same one you use to access webmail account What errors are you getting ? Does it prompt for password ? Please post image of any error you see or tell us word for word what it says. Do you have a problem sending emails from those accounts as well as receiving? I was just about to post this when I've just noticed you asked this question on the 12th July but never posted requested info - you need respond. Please do not create another question - please keep all correspondence in the same question in order to maintain continuity of conversation and prevent repetition. What does it say in the 'Tools' > 'Activity Manager' ? Could you be getting new mail but cannot see them ? Check you have the following: * View > Folders > All * View > Threads > All Does the Quick Filter Bar have any highlighted icons - so a filter of the view is being applied - if yes, click on those highlighted icons to deselect them. Have you created any Message Filters ? If yes, then disable them to see if it is effecting the situation - Also check the 'Filter Log' - assuming you have enabled it - to see what is filtered to where. Are these gmx accounts all set up as new accounts and you have never managed to get them to work or did they work ok and suddenly stop ?