Issues with IP Blocking in Mailcow When Adding Multiple Email Accounts

orkun12tr

Hello everyone,

I am currently facing a small issue with our company’s email system, which uses Mailcow. I need to set up five email accounts on a single computer, but when I add the third email, the system automatically bans our company’s IP address. As a result, we are unable to connect through Outlook and I need to restart Mailcow to proceed with adding the remaining two email accounts.

Additionally, some computers in our company are unable to send or receive emails. However, these computers can send and receive emails from home or any other different IP address. It seems our company’s IP is consistently getting banned.

Has anyone else experienced similar issues with Mailcow? Any suggestions or solutions would be greatly appreciated.

Thank you in advance for your help!

faisal

Looks like Outlook is trying to connect via MAPI without authenticating and it’s triggering netfilter. Have you tried to whitelist your IP in System -> Configuration -> Fail2ban parameters

ETNyx

You can see some ok logins, last column is quite verbose, if so, there is no POP3, that is protocol what you are using in Outlook. So I guess you must allow POP3. You can allow/disable protocols per mailbox settings in admin under “Allowed protocols”.

Or try to use IMAP in your Outlook settings,…

orkun12tr

Hello, thank you for your response. The problem seems to be resolved after whitelisting the IP. Since 50 employees are constantly using the mail system from a single IP, it perceives this as an attack and bans it.