Re: [Fail2ban-users] Need SMTP Ban help

[Jody W. <jo...@jo...>]

I’ve tested my MTU settings and they’re working perfectly fine, so it wouldn’t be on my end for an MTU thing.

I also did another lookup of the "offending" IPs and they’re all coming from CloudFlare, which is a bit baffling to me as I’m not using CloudFlare. Which begs the question, why is CloudFlare attempting to connect to my email server.

Jody

> On May 17, 2018, at 2:24 AM, Yves via Fail2ban-users <fai...@li...> wrote:
> 
>> I'd also check your IPv6 connectivity (including ICMPv6) to the client, these timeouts are more likely caused by MTU problems than malicious intent.
> I wouldn't know, but if you're right, this is indeed the _first_ thing to check! :-)