Client IP Addresses keep getting blocked

[digitalrefresh]

Hello

I have had CFS installed on one of my servers and it's been working great, but I keep running into problems where by if a client tries to access their email accounts from an IP other than the one they have been using normally, the IP address get blocked and they cannot access either their website or emails until I allow it on the server.

This has been happening for some time and I'm not sure why because it's not like there are any incorrect login's or failed password attempts to refer to, it is simply if a client goes to use their emails at another address, that address gets instantly banned. For example my client takes their laptop home and logs onto their email, blacklisted and banned from the server immediately. It is as if any activity on the domain other than at a single IP address is banned.

I have tried looking through any settings to see if there is something that may be checked which is causing it, but I am drawing a blank.

Does anyone know why this could be happening or an idea of what may be causing it?

Thanks, William

[Sergio]

Every time that an IP is blocked, CSF sends an email telling about the block.
Can you post (changing sensitive info) what the email says?
Remember to replace the email address and the IPs involved for security reasons.