DoH plugin for BIND

Reindl Harald h.reindl at
Sat May 2 15:03:00 UTC 2020

Am 02.05.20 um 16:39 schrieb Paul Kosinski via bind-users:
> I wasn't complaining about port 25, I was just citing it as a
> counterexample to the claim that ISPs "must" pass all traffic.

> I think that most ISPs tell customers how to set up their email clients
> (NUAs) including what port to use. Of course it seems that now most
> people use Web based email like Gmail, Yahoo (and even Comcast/Xfinity)
> so they never see port numbers.
> On Sat, 2 May 2020 15:51:58 +0200
> Reindl Harald <h.reindl at> wrote:
>> Am 02.05.20 um 15:41 schrieb Michael De Roover:
>>> In my experience and from what I've heard, very few.   
>> if that would be true how comes that most mail clients still default to
>> 25 for submission and years after closing port 25 on our mailserver i
>> still struggle with customers smartphones still not using 587?
>> in fact 10 years ago some ISP's *tried* to kill outbound port 25 because
>> there is no point in using it from a homemachine and at that time we
>> struggeled also to explain our customers that 25 is plain wrong
>> finally they gave up because the damage of open port 25 is killed with
>> dnsbl but the customer support went crazy with "why can't i send email
>> with my internet connection"
>>> Even if your ISP allows it, chances are that other mail servers will reject it  
>> that's a completl different story
>>> On 5/2/20 3:30 PM, Paul Kosinski via bind-users wrote:  
>>>> How many ISPs allow traffic on port 25? My impression is that even many
>>>> (non-enterprise) business customers can't use port 25  

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